Inter- and Intramolecular Proton Transfer in an Isolated (Cytosine-Guanine)H+ Pair: Direct Evidence from IRMPD Spectroscopy.

The collision-induced dissociation of the protonated cytosine-guanine pair was studied using tandem mass spectrometry (MS3) coupled to infrared multiple photon dissociation spectroscopy with the free electron laser at Orsay (CLIO) to determine the structure of the CH+ and GH+ ionic fragments. The results were rationalized with the help of electronic structure calculations at the density functional theory level with the B3LYP/6-311++G(3df,2p) method. Several tautomers of each fragment were identified for the first time, some of which were previously predicted by other authors. In addition, two unexpected and minor tautomers were also found: cytosine keto-imino [CKI(1,2,3,4)H+] and guanine keto-amino [GKA(1,3,7)H+]. These results highlight the importance of the DNA base tautomerization assisted by inter- and intramolecular proton or hydrogen transfer within the protonated pairs.

Infrared Multiple Photon Dissociation Spectroscopy of Protonated Cyameluric Acid.

The present study reports the first structural characterization of protonated cyameluric acid ([CA + H]+) in the gas phase, which paves the way for prospective bottom-up research on the condensed-phase chemistry of CA in the protonated form. A number of [CA + H]+ keto-enol isomers can a priori be produced as a result of protonation at available N and O positions of precursor neutral CA tautomers, yet ab initio computations predict different reduced [CA + H]+ isomer populations dominating the solution and gas phases that are involved in the ion generation process (i.e., electrospray ionization). Infrared multiple photon dissociation spectra were recorded in the 990-1900 and 3300-3650 cm-1 regions and compared with theoretical [B3LYP/6-311++G(d,p)] IR absorption spectra of several [CA + H]+ isomers, providing a satisfactory agreement for the most stable monohydroxy form in the gas phase, [1358a]+, yet the contribution of its nearly isoenergetic OH rotamer, [1358b]+, cannot be neglected. This is indicative of the occurrence of [CA + H]+ isomer interconversion reactions, assisted by protic solvent molecules, during their transfer into the gas phase. The results suggest that available O positions on neutral CA are energetically favored protonation sites in the gas phase.

On the Interaction between Deprotonated Cytosine [C(-H) ]- and Ba2+ : Infrared Multiphoton Spectroscopy and Dynamics.

Gas-phase interactions between Ba2+ and deprotonated cytosine (C(-H) ) were studied in [C(-H) Ba]+ and [C(-H) BaC]+ complexes by IRMPD spectroscopy coupled to tandem mass-spectrometry in combination with DFT calculations. For the [C(-H) BaC]+ complex only one [C(-H) KAN1O-Ba-Canti ]+ isomer was found, although the presence of another structure cannot be excluded. This isomer features a central tetracoordinated Ba2+ that simultaneously interacts with keto-amino [C(-H) ]- deprotonated on N1 and neutral keto-amino C. Both moieties are in different planes as a consequence of an additional NH…O=C hydrogen bond between C and [C(-H) ]- . A sequential IRMPD dynamics is observed in this complex. For the [C(-H) Ba]+ complex produced by electrospray ionization two isomers ([C(-H) KAN1OBa]+ and [C(-H) KAN3OBa]+ ) were identified, in which Ba2+ interacts simultaneously with the C=O group and the N1 or N3 atom of the keto-amino [C(-H) ]- , respectively. A comparison with the related [C(-H) Pb]+ complex (J. Y. Salpin et al., Chem. Phys. Chem. 2014, 15, 2959-2971) is also presented.

UV Photofragmentation of Cold Cytosine-M+ Complexes (M+: Na+, K+, Ag+).

The UV photofragmentation spectra of cold cytosine-M+ complexes (M+: Na+, K+, Ag+) were recorded and analyzed through comparison with geometry optimizations and frequency calculations of the ground and excited states at the SCS-CC2/Def2-SVPD level of theory. While in all complexes, the ground state minimum geometry is planar (Cs symmetry), the ππ* state minimum geometry has the NH2 group slightly twisted and an out-of-plane metal cation. This was confirmed by comparing the simulated ππ* Franck-Condon spectra with the vibrationally resolved photofragmentation spectra of CytNa+ and CytK+. Vertical excitation transitions were also calculated to evaluate the energies of the CT states involving the transfer of an electron from the Cyt moiety to M+. For both CytK+ and CytNa+ complexes, the first CT state corresponds to an electron transfer from the cytosine aromatic π ring to the antibonding σ* orbital centered on the alkali cation. This πσ* state is predicted to lie much higher in energy (>6 eV) than the band origin of the π-π* electronic transition (around 4.3 eV) unlike what is observed for the CytAg+ complex for which the first excited state has a nOσ* electronic configuration. This is the reason for the absence of the Cyt+ + M charge transfer fragmentation channel for CytK+ and CytNa+ complexes.

Safety and Efficacy of Endovascular Coils and Non-Flow-Diverting Stents for Management of Unruptured Intracranial Aneurysms: A Location-Specific Outcomes Analysis.

INTRODUCTION: The relationship between the anatomical location of an unruptured saccular aneurysm, the efficacy, and the potential complications associated with coil and non-flow-diverting stents remains poorly documented. Therefore, the aim of this study is to evaluate the efficacy and safety of endovascular treatment based on the anatomical position of the unruptured intracranial aneurysm (UIA). METHODS: A retrospective cohort study was conducted using an anonymized database of patients who underwent endovascular therapy for UIAs between 2014 and 2021. RESULTS: A total of 138 patients with 147 UIAs were included. Immediate Raymond-Roy occlusion class I or II was achieved in 99.2% of patients in all anatomical locations, with a 96.2% occlusion rate at the 12-month follow-up. Complications occurred more frequently in the anterior cerebral artery (35%) and internal carotid artery in its ophthalmic segment (25%). However, the difference was not statistically significant. CONCLUSIONS: Our study shows that endovascular treatment with stents and coils is effective and safe for managing UIAs in various anatomical locations. The incidence of thromboembolic complications was significantly higher for UIAs located in the anterior cerebral artery.

A Study on the Efficacy and Safety of Pipeline Shield Stents and Nonmodified Surface Flow-Diverting Stents in Patients with Intracranial Aneurysms.

BACKGROUND: Few studies have compared the Pipeline Shield stents with previous generations of flow-diverting stents (FDSs) for the treatment of unruptured intracranial aneurysms. This study aimed to evaluate the efficacy and safety of Pipeline Shield stents and FDSs without modified surfaces. METHODS: The present evaluation is a retrospective cohort study of patients endovascularly treated with Pipeline Shield stents or FDSs without modified surfaces for unruptured intracranial aneurysms between January 2014 and June 2022. The data analyzed were obtained from the anonymized database of our institution's interventional radiology service. RESULTS: A total of 147 patients with 155 unruptured intracranial aneurysms were included. Of the 155 aneurysms, 96 were treated with Pipeline Shield stents and 59 with FDSs without modified surfaces. The aneurysms treated with Pipeline Shield stents had higher 6-month (O'Kelly-Marotta [OKM] D; 87.5% vs. 71.4%; P = 0.025) and 1-year (OKM D; 82.5% vs. 63.0%; P = 0.047) occlusion rates than the aneurysms treated using FDSs without modified surfaces. No differences between the devices were found at the 1-year follow-up in the incidence of ischemic stroke (P = 0.939) or hemorrhagic complications (P = 0.559). CONCLUSIONS: Pipeline Shield stents demonstrated superior complete occlusion rates (OKM D) at both the 6-month and the 1-year follow-up assessments compared with nonmodified surface FDSs. No significant differences were found in the safety profiles between the 2 types of stents with regard to thromboembolic complications and ischemic events. Further research with larger study populations is necessary to validate these findings.

Geometry of intracranial aneurysms and of intrasaccular devices may influence aneurysmal occlusion rates after endovascular treatment.

INTRODUCTION: The Woven EndoBridge device (WEB) is used to treat wide-neck bifurcation aneurysms. These devices are deployed inside the sac. Therefore, the mesh structure provides apposition with the aneurysm wall and induces aneurysmal thrombosis. The objective of our study was to evaluate the anatomic and device-related parameters and indexes with Computational Fluid Dynamics (CFD) of the intracranial aneurysms before and after WEB simulation and find their relationship to complete occlusion. MATERIALS AND METHODS: Using the heterogeneous model based on the marching cubes algorithm, we created 3D representations of 27 bifurcated intracranial aneurysms treated with the single-layer WEB device to evaluate anatomic and device-related parameters with CFD. RESULTS: In our CFD analysis, we observed higher large volumes (Va) (0.25 ± 0.18 versus 0.39 ± 0.09, p-value= 0.025) and higher volume to neck surface ratio (Ra) (1.32 ± 0.17 versus 1.54 ± 0.14, p-value= 0.021) in cases with occlusion failure. CONCLUSIONS: Large aneurysm volumes (Va) and higher volume to neck surface ratio (Ra) could be associated with occlusion failure in aneurysms treated with the WEB device.

Heterogeneous model to evaluate CFD in intracranial bifurcation aneurysms treated with the WEB device to predict angiographic outcome.

INTRODUCTION: The Woven EndoBridge device (WEB) was developed as an alternative to treat Wide-Necked bifurcation aneurysms. It has proven to be effective and safe, however, cases of recanalization have been reported. The purpose of this study was to evaluate and quantify hemodynamic parameters and indexes with CFD of the intracranial aneurysms before and after WEB simulation and to establish their relationship to complete occlusion. MATERIALS AND METHODS: Using the heterogeneous model based on the marching cubes algorithm, we created 3D representations of 27 bifurcated intracranial aneurysms treated with the single-layer WEB device to evaluate hemodynamics parameters with CFD, calculated with and without the WEB. RESULTS: We observed a lower treatment entry concentration indices (ICI) (2.12 ± 1.31 versus 3.14 ± 0.93, p-value: 0.029) previous to placement of WEB and higher pre-treatment FN (7.56 ± 5.92 versus 3.35 ± 1.51, p-value: 0.018) and post-treatment FN (5.34 ± 5.89 versus 1.99 ± 0.83, p-value: 0.021) for cases with successful occlusions. Lower post-treatment SRa (197.81 ± 221.29 versus 80.02 ± 45.25, p-value: 0.044) and higher pre (0.11 ± 0.07 versus 0.25 ± 0.19, p-value: 0.011) and post-treatment MATT (0.69 ± 1.23 versus 1.02 ± 0.46, p-value: 0.006) were observed in non-occluded cases. CONCLUSIONS: In our CFD analysis of the hemodynamic parameters of IA, we found lower ICI before the placement of the WEB device and higher FN pre- and post-treatment for cases with successful occlusions. Non-occluded cases had lower post-treatment SRa and higher pre-treatment and post-treatment MATT.

The Woven EndoBridge device, an effective and safe alternative endovascular treatment of intracranial aneurysm-systematic review.

PURPOSE: This study is a systematic review about the WEB device and addresses the efficacy and safety of this device for the endovascular treatment of ruptured and unruptured intracranial aneurysms. MATERIAL AND METHODS: This systematic literature review followed PRISMA-P guidelines and included studies published until 2010. PubMed and ScienceDirect databases were searched, resulting in 22 articles meeting the inclusion criteria. RESULTS: The studies involved 1705 patients and 1224 aneurysms, predominantly wide-neck aneurysms in the middle cerebral artery, internal carotid artery, and basilar artery. The treatment success rate was 28.1%, with the WEB-SL and WEB-SLS devices being commonly used. The immediate post-treatment adequate occlusion rate was 33.3%, increasing to 49.7% at follow-up. Thromboembolic complications occurred in 6.5% of cases, while other complications were observed in 3.1% of cases. The mortality rate associated with the WEB device was low, approximately 1%. CONCLUSION: The WEB device demonstrates favorable outcomes in treating patients with intracranial aneurysms, with adequate occlusion rates improving over time. Thromboembolic complications are the primary concern, but overall complication and mortality rates remain low. Further research is needed to optimize device selection, standardize classification systems, and enhance long-term evaluation and training protocols.

Successful Endovascular Treatment of a Traumatic Cervical Arteriovenous Fistula After a Carotid Paraganglioma Resection: A Case Report.

Traumatic cervical arteriovenous fistulas are rare, accounting for only 4% of all arteriovenous fistulas. They can be caused by penetrating, or rarely, blunt trauma, resulting in high-pressure arterial blood draining directly into a vein, decreasing distal perfusion. They are seldom reported as a complication of a carotid paraganglioma surgical resection. Historically, arteriovenous fistulas were treated initially conservatively, after that, surgically; nowadays, endovascular treatment, when feasible, is the preferred method as it offers advantages over surgery. This case report describes a rare traumatic cervical arteriovenous fistula that developed after a carotid paraganglioma resection and was successfully treated using coils and Onyx embolic agent via endovascular embolization. After successful embolization, the patient had a smooth recovery and remained stable. In conclusion, vascular injury seems to be the only constant in all acquired cervical arteriovenous fistulas independent of the trauma mechanism; and endovascular treatment, when feasible, is preferred over surgery as it offers superior advantages.

Clinical perspective in relation to age in patients treated with thrombectomy for anterior circulation stroke in a stroke center in Colombia.

BACKGROUND AND AIMS: Endovascular treatment for cerebrovascular disease is accepted as a first-line option with level I evidence in patients with an early and late time of window of onset symptoms, and an additional option in patients who do not respond or with contraindications to systemic thrombolysis; nevertheless the efficacy and outcomes of some groups were not clear, one of them are patients aged 80 years and older, because they were excluded of the trials, so the evidence is controversial with significant heterogeneity, for that reason in our study, we decided to analyze the age in the patients treated in our stroke center, as a predictor of prognosis, and to provide a baseline for the establishment of personalized treatment plans. METHODS: Observational, retrospective study of patients that received endovascular treatment for cerebrovascular disease in a Colombian stroke center between 2016 and 2020, continuous and categorical variables were compared using the Student's t test and Chi-Square. To determine cut-off points in the variable against death and Rankin score variable on 90th day. RESULTS: In total, 108 patients were recruited, 35 of them were of 80 or more years, and the mean age was 72.7 years, we found age as a significant variable to predict the risk in the population over 80 years of age [RR 3.37 CI (95% 1.14-103) p = 0.029]. CONCLUSIONS: Age younger than 80 is a significant predictor for results and long-term outcomes in patients suffering from stroke, and in patients older than 80 years old a Thrombolysis in Cerebral Infarction score 2b-3 is a predictor of good outcomes. Further studies are needed to evaluate the relationship between intrahospital complications and long-term outcomes.

Validation of three-dimensional printed models of intracranial aneurysms.

INTRODUCTION: Three-dimensional (3D) printing has evolved for medical applications as it can produce customized 3D models of devices and implants that can improve patient care. In this study, we aimed to validate the geometrical accuracy of the 3D models of intracranial aneurysms printed using Stereolithography 3D printing technology. MATERIALS AND METHODS: To compare the unruptured intracranial aneurysm mesh between the five patients and 3D printed models, we opened the DICOM files in the Sim&Size® simulation software, selected the region of interest, and performed the threshold check. We juxtaposed the 3D reconstructions and manually rotated the images to get the same orientation when needed and measured deviations at different nodes of the patient and 3D printed model meshes. RESULTS: In the first patient, 80% of the nodes were separated by <0.56 mm and 0.17 mm. In the second patient, the deviations were below 0.17 mm for 80% of the meshes' nodes. In the next three patients, the deviations were below 0.21, 0.23, and 0.11 mm for 80% of the meshes' nodes. Finally, the overall deviation was below 0.21 mm for 80% of the mesh nodes of the five aneurysms. CONCLUSIONS: 3D printed models of intracranial aneurysms are accurate, having surfaces that resemble that of patients' angiographies with an 80% cumulative deviation below 0.21 mm.

Guanine Tautomerism in Ionic Complexes with Ag+ Investigated by IRMPD Spectroscopy and Mass Spectrometry.

In this paper, we present the IRMPD spectra of three ionic complexes between guanine (G) and silver (Ag+): [GAg-H2O]+, [GAgG]+ produced in the electrospray ionization source of the mass spectrometer, and [GAg]+ produced by collision induced dissociation of the [GAgG]+ complex. On the basis of the comparison of theoretically calculated IR spectra, we show that there are two isomers of each complex containing two different keto-amino (KA) tautomers of G (GKA(1,9) and GKA(1,7)). The observed isomers are the most stable structures in aqueous solution, and their experimentally estimated relative populations are in better agreement with the calculated relative populations in solution than in the gas phase, both at 298 K. We concluded that these observations suggest that GKA(1,9) and GKA(1,7) coexist in solution according to previous theoretical reports (Colominas, C.; et al. J. Am. Chem. Soc. 1996, 118, 6811). We were unable to find any evidence of the presence of the GEA(9), GKA(3,7), GKA(3,9), or GKA(7,9), whose relative stabilities in solution are strongly dependent on the theoretical method used to account for the solvent effect (Hanus, M.; et al. J. Am. Chem. Soc. 2003, 125, 7678).

Actividad biológica de los aceites de semillas de Annona muricatay A. cherimola / Biological activity of Annona muricata and A. cherimola seed oils

Vegetable extracts have become important raw materials for food, pharmaceutical and cosmetic industries because of their biological potential. The objective of this study was to assess the biological activity of vegetable oils (VOs) extracted from Annona muricata and A. cherimola. Antibacterial activity was determined by plaque microdilution. The assessment of hemolytic inhibition and morphological alterations was performed in erythrocyte cultures by spectrophotometry and microscopy, respectively. Neutrophils were used to analyze both cytotoxicity by the trypan blue exclusion method and the effect on gelatinase granule release (MMP9) via zymography. Whereas VOs showed a mild antibacterial activity (900 µL/mL) on five ATCC bacterial strains, they had no effect on multi-resistant bacteria. In addition, VOs inhibited hydrogen peroxide induced hemolysis and did not cause erythrocyte cell abnormalities. Cytotoxicity was not detected in neutrophils and VOs were able to stimulate MMP9 release. These results support their potential use by the food and cosmetic industries due to their antioxidant, non-cytotoxic, and slight antibacterial capacities.

Los extractos vegetales adquieren importancia en la industria alimentaria, farmacéutica y cosmética, por su potencial biológico. El objetivo de este estudio fue evaluar actividad biológica de los Aceites Vegetales (AV) de semillas de Annona muricata y A. cherimola. La actividad antibacteriana se determinó mediante microdilución en placa; en cultivo de eritrocitos se evaluó inhibición hemolítica por espectrofotometría y alteraciones morfológicas por recuento microscópico; en neutrófilos se evaluó citotoxicidad por método de exclusión con azul de tripán, y el efecto sobre liberación de gránulos de gelatinasa (MMP9) mediante zimografía. Los AV presentaron actividad antibacteriana leve (900 µL/mL) en cinco cepas ATCC, pero no en bacterias multirresistentes; inhibieron la hemolisis inducida por peróxido de hidrogeno; no generaron deformaciones eritrocitarias; no se evidenció citotoxicidad en neutrófilos y estimularon la liberación de MMP9. Los resultados podrían sustentar el uso potencial de estos AV en la industria alimenticia o cosmética, gracias a su capacidad antioxidante, no citotóxica y levemente antibacteriana.

Fingerprints of Both Watson-Crick and Hoogsteen Isomers of the Isolated (Cytosine-Guanine)H+ Pair.

 Gas phase protonated guanine-cytosine (CGH+) pair was generated using an electrospray ionization source from solutions at two different pH (5.8 and 3.2). Consistent evidence from MS/MS fragmentation patterns and differential ion mobility spectra (DIMS) point toward the presence of two isomers of the CGH+ pair, whose relative populations depend strongly on the pH of the solution. Gas phase infrared multiphoton dissociation (IRMPD) spectroscopy in the 900-1900 cm-1 spectral range further confirms that the Watson-Crick isomer is preferentially produced (91%) at pH = 5.8, while the Hoogsteen isomer predominates (66%) at pH = 3.2). These fingerprint signatures are expected to be useful for the development of new analytical methodologies and to trigger isomer selective photochemical studies of protonated DNA base pairs.