Características clínicas e histopatológicas de melanoma subungueal en 57 pacientes mexicanos: una cohorte de 5 años / Clinical and Histopathologic Features of Subungual Melanoma in 57 Mexican Patients: A 5-Year Cohort Study

El melanoma subungueal es un tumor poco común, con peor pronóstico comparado con los de otras localizaciones. Corresponde al 1-23% de los melanomas, según la población. El objetivo de este estudio fue describir las características clínicas e histopatológicas del melanoma subungueal en la población mexicana. Se incluyeron 57 pacientes con melanoma subungueal (19% de los 303 melanomas totales), con una mediana de edad de 71 años. La localización predominante fueron los miembros inferiores (52,6% de los melanomas subungueales) y el primer dedo (75,4% de los casos). El subtipo histológico más frecuente fue el acral lentiginoso (50,9%). La mediana de Breslow fue de 3mm. El estadio IA fue el más frecuente (28,1%). Se encontró una tasa de recurrencia del 19,3% y de metástasis del 8,8%. Las características clínico-patológicas fueron semejantes a lo descrito en la literatura. Es importante realizar un diagnóstico y tratamiento tempranos de cara a mejorar su pronóstico.(AU)

Although subungual melanoma is uncommon, it is associated with worse outcomes than melanomas in other locations and accounts for 1% to 23% of all melanomas, depending on the population. The aim of this study was to describe the clinical and histopathologic features of subungual melanoma in a Mexican population. We identified 303 patients with melanoma, and of these, 19% (57 patients with a median age of 71 years) had subungual melanoma. The main sites affected were the lower limbs (52.6%) and the toe (75.4%). The most common histologic subtype was acral lentiginous melanoma (50.9%). Median Breslow thickness was 3 mm, and stage IA tumors were the most common (in 28.1% of patients). Recurrence and metastasis occurred in 19.3% and 8.8% of patients, respectively. The clinical and histopathologic features identified are similar to those described in the literature. Early diagnosis and treatment are crucial for improving prognosis.(AU)

[Translated article] Clinical and Histopathologic Features of Subungual Melanoma in 57 Mexican Patients: A 5-Year Cohort Study / Características clínicas e histopatológicas de melanoma subungueal en 57 pacientes mexicanos: una cohorte de 5 años

El melanoma subungueal es un tumor poco común, con peor pronóstico comparado con los de otras localizaciones. Corresponde al 1-23% de los melanomas, según la población. El objetivo de este estudio fue describir las características clínicas e histopatológicas del melanoma subungueal en la población mexicana. Se incluyeron 57 pacientes con melanoma subungueal (19% de los 303 melanomas totales), con una mediana de edad de 71 años. La localización predominante fueron los miembros inferiores (52,6% de los melanomas subungueales) y el primer dedo (75,4% de los casos). El subtipo histológico más frecuente fue el acral lentiginoso (50,9%). La mediana de Breslow fue de 3mm. El estadio IA fue el más frecuente (28,1%). Se encontró una tasa de recurrencia del 19,3% y de metástasis del 8,8%. Las características clínico-patológicas fueron semejantes a lo descrito en la literatura. Es importante realizar un diagnóstico y tratamiento tempranos de cara a mejorar su pronóstico.(AU)

Although subungual melanoma is uncommon, it is associated with worse outcomes than melanomas in other locations and accounts for 1% to 23% of all melanomas, depending on the population. The aim of this study was to describe the clinical and histopathologic features of subungual melanoma in a Mexican population. We identified 303 patients with melanoma, and of these, 19% (57 patients with a median age of 71 years) had subungual melanoma. The main sites affected were the lower limbs (52.6%) and the toe (75.4%). The most common histologic subtype was acral lentiginous melanoma (50.9%). Median Breslow thickness was 3 mm, and stage IA tumors were the most common (in 28.1% of patients). Recurrence and metastasis occurred in 19.3% and 8.8% of patients, respectively. The clinical and histopathologic features identified are similar to those described in the literature. Early diagnosis and treatment are crucial for improving prognosis.(AU)

Experimental characterization of SiCH+via single-photon ionization of gas-phase SiCH.

SiCH and its cation have consistently emerged as predicted species in models of silicon chemistry within the interstellar medium, although they remain unobserved in space. Hindered by their intrinsic instability, no spectroscopic insights have been gleaned concerning the SiCH+ cation. In this study, we present experimental measurements on the SiCH+ cation through single-photon ionization spectroscopy of the SiCH radical within the 8.0-11.0 eV range. Gas-phase SiCH radicals were generated through chemical reactions involving CHx (x = 0-3) and SiHy (y = 0-3) within a microwave discharge flow-tube reactor. Employing a double imaging photoelectron/photoion coincidence spectrometer on the DESIRS beamline at the SOLEIL synchrotron, we recorded mass-selected ion yield and photoelectron spectra. From the analysis of the photoelectron spectrum supported by ab initio calculations and Franck-Condon simulations, the adiabatic ionization energies for the transitions from the X2Π ground electronic state of SiCH toward the X+3Σ- and A+3Π electronic states of SiCH+ have been derived [8.935(6) and 10.664(6) eV, respectively, without spin-orbit correction]. The contribution from the less stable isomer HSiC has been explored in our analysis and ruled out in our experiments.

[Translated article] Clinical and Histopathologic Features of Subungual Melanoma in 57 Mexican Patients: A 5-Year Cohort Study.

Although subungual melanoma is uncommon, it is associated with worse outcomes than melanomas in other locations and accounts for 1% to 23% of all melanomas, depending on the population. The aim of this study was to describe the clinical and histopathologic features of subungual melanoma in a Mexican population. We identified 303 patients with melanoma, and of these, 19% (57 patients with a median age of 71 years) had subungual melanoma. The main sites affected were the lower limbs (52.6%) and the toe (75.4%). The most common histologic subtype was acral lentiginous melanoma (50.9%). Median Breslow thickness was 3 mm, and stage IA tumors were the most common (in 28.1% of patients). Recurrence and metastasis occurred in 19.3% and 8.8% of patients, respectively. The clinical and histopathologic features identified are similar to those described in the literature. Early diagnosis and treatment are crucial for improving prognosis.

Clinical and Histopathologic Features of Subungual Melanoma in 57 Mexican Patients: A 5-Year Cohort Study. / Características clínicas e histopatológicas de melanoma subungueal en 57 pacientes mexicanos: una cohorte de 5 años.

Although subungual melanoma is uncommon, it is associated with worse outcomes than melanomas in other locations and accounts for 1% to 23% of all melanomas, depending on the population. The aim of this study was to describe the clinical and histopathologic features of subungual melanoma in a Mexican population. We identified 303 patients with melanoma, and of these, 19% (57 patients with a median age of 71 years) had subungual melanoma. The main sites affected were the lower limbs (52.6%) and the toe (75.4%). The most common histologic subtype was acral lentiginous melanoma (50.9%). Median Breslow thickness was 3 mm, and stage IA tumors were the most common (in 28.1% of patients). Recurrence and metastasis occurred in 19.3% and 8.8% of patients, respectively. The clinical and histopathologic features identified are similar to those described in the literature. Early diagnosis and treatment are crucial for improving prognosis.

Single-photon ionization of SiC in the gas phase: experimental and ab initio characterization of SiC.

We report the first experimental observation of single-photon ionization transitions of the SiC radical between 8.0 and 11.0 eV performed on the DESIRS beamline at the SOLEIL synchrotron facility. The SiC radical, very difficult to synthesize in the gas phase, was produced through chemical reactions between CHx (x = 0-3) and SiHy (y = 0-3) in a continuous microwave discharge flow tube, the CHx and SiHy species being formed by successive hydrogen-atom abstractions induced by fluorine atoms on methane and silane, respectively. Mass-selected ion yield and photoelectron spectra were recorded as a function of photon energy using a double imaging photoelectron/photoion coincidence spectrometer. The photoelectron spectrum enables the first direct experimental determinations of the X+ 4Σ- ← X 3Π and 1+ 2Π â† X 3Π adiabatic ionization energies of SiC (8.978(10) eV and 10.216(24) eV, respectively). Calculated spectra based on Franck-Condon factors are compared with the experimental spectra. These spectra were obtained by solving the rovibrational Hamiltonian, using the potential energy curves calculated at the multireference single and double configuration interaction level with Davidson correction (MRCI + Q) and the aug-cc-pV5Z basis set. MRCI + Q calculations including the core and core-valence electron correlation were performed using the aug-cc-pCV6Z basis set to predict the spectroscopic properties of the six lowest electronic states of SiC+. Complete basis set extrapolations and relativistic energy corrections were also included in the determination of the energy differences characterizing the photoionization process. Using our experimental and theoretical results, we derived semi-experimental values for the five lowest ionization energies of SiC.

Isolation and characterization of farm pig adipose tissue-derived mesenchymal stromal/stem cells.

Adipose tissue-derived mesenchymal stromal/stem cells (ASCs) are considered important tools in regenerative medicine and are being tested in several clinical studies. Porcine models are frequently used to obtain adipose tissue, due to the abundance of material and because they have immunological and physiological similarities with humans. However, it is essential to understand the effects and safe application of ASCs from pigs (pASCs) as an alternative therapy for diseases. Although minipigs are easy-to-handle animals that require less food and space, acquiring and maintaining them in a bioterium can be costly. Thus, we present a protocol for the isolation and proliferation of ASCs isolated from adipose tissue of farm pigs. Adipose tissue samples were extracted from the abdominal region of the animals. Because the pigs were not raised in a controlled environment, such as a bioterium, it was necessary to carry out rigorous procedures for disinfection. After this procedure, cells were isolated by mechanical dissociation and enzymatic digestion. A proliferation curve was performed and used to calculate the doubling time of the population. The characterization of pASCs was performed by immunophenotyping and cell differentiation in osteogenic and adipogenic lineages. The described method was efficient for the isolation and cultivation of pASCs, maintaining cellular attributes, such as surface antigens and multipotential differentiation during in vitro proliferation. This protocol presents the isolation and cultivation of ASCs from farm pig as an alternative for the isolation and cultivation of ASCs from minipigs, which require strictly controlled maintenance conditions and a more expensive process.

Probing the dynamics of the photo-induced decarboxylation of neutral and ionic pyruvic acid.

The dynamics of the electronically excited pyruvic acid (PA) and of its unimolecular decomposition upon single photon ionisation are investigated by means of a table top fs laser and VUV synchrotron radiation. The latter is coupled with photo-ion/photo-electron coincidence acquisition devices that allow the identification of the ionic products coming from state-to-state fragmentation upon ionisation. The fs-based setup provides time-resolved mass spectra with 266 nm (= 4.661 eV) excitation and an 800 nm multiphoton probe. For interpretation, we carried out theoretical computations using a composite scheme combining density functional theory full molecular geometric optimisation and post-Hartree-Fock correction inclusion. We therefore determined the neutral and ionic species formed during these experiments and the corresponding dissociation channels. Although several PA isomers are found, we show that solely the most stable isomer of PA (i.e. Tc) is present in the molecular beam prior to ionisation. We determined its adiabatic ionisation energy (AIE = 10.031 ± 0.005 eV). The fragmentation of the Tc+ ion occurs at ∼0.4 eV above the threshold and it is dominated by the CC bond breaking channel, forming the HOCO fragment in conjunction with the CH3CO+ ion. The decarboxylation of Tc+ channels has a minor contribution, although they are more favourable thermodynamically. These findings are in contrast with the dominance of decarboxylation while fragmenting Tc populated in the S1-S3 states. For explanation, we invoke an indirect process populating first a short lived autoionising neutral state located in energy at the HOCO + CH3CO+ dissociation limit. Later on, fragmentation occurs, followed by autoionisation. On the other hand, the fs-based experiment does not reveal any appreciable dynamics for the Tc isomer of PA after a 266 nm excitation because of non-favourable Franck-Condon factors at this energy. In sum, our work highlights the importance of the couplings between the parent ion vibrational modes and the dissociative channels in the vicinity of the loss ionic fragmentation thresholds.

Threshold photoelectron spectroscopy of 9-methyladenine: theory and experiment.

We present a combined experimental and theoretical study of single-photon ionization of 9-methyladenine (9MA) in the gas phase. In addition to tautomerism, several rotamers due to the rotation of the methyl group may exist. Computations show, however, that solely one rotamer contributes because of low population in the molecular beam and/or unfavorable Franck-Condon factors upon ionization. Experimentally, we used VUV radiation available at the DESIRS beamline of the synchrotron radiation facility SOLEIL to record the threshold photoelectron spectrum of this molecule between 8 and 11 eV. This spectrum consists of a well-resolved band assigned mainly to vibronic levels of the D0 cationic state, plus a contribution from the D1 state, and two large bands corresponding to the D1, D2 and D3 electronically excited states. The adiabatic ionization energy of 9MA is measured at 8.097 ± 0.005 eV in close agreement with the computed value using the explicitly correlated coupled cluster approach including core valence, scalar relativistic and zero-point vibrational energy corrections. This work sheds light on the complex pattern of the lowest doublet electronic states of 9MA+. The comparison to canonical adenine reveals that methylation induces further electronic structure complication that may be important to understand the effects of ionizing radiation and the charge distribution in these biological entities at different time scales.

Isolation and characterization of farm pig adipose tissue-derived mesenchymal stromal/stem cells

Adipose tissue-derived mesenchymal stromal/stem cells (ASCs) are considered important tools in regenerative medicine and are being tested in several clinical studies. Porcine models are frequently used to obtain adipose tissue, due to the abundance of material and because they have immunological and physiological similarities with humans. However, it is essential to understand the effects and safe application of ASCs from pigs (pASCs) as an alternative therapy for diseases. Although minipigs are easy-to-handle animals that require less food and space, acquiring and maintaining them in a bioterium can be costly. Thus, we present a protocol for the isolation and proliferation of ASCs isolated from adipose tissue of farm pigs. Adipose tissue samples were extracted from the abdominal region of the animals. Because the pigs were not raised in a controlled environment, such as a bioterium, it was necessary to carry out rigorous procedures for disinfection. After this procedure, cells were isolated by mechanical dissociation and enzymatic digestion. A proliferation curve was performed and used to calculate the doubling time of the population. The characterization of pASCs was performed by immunophenotyping and cell differentiation in osteogenic and adipogenic lineages. The described method was efficient for the isolation and cultivation of pASCs, maintaining cellular attributes, such as surface antigens and multipotential differentiation during in vitro proliferation. This protocol presents the isolation and cultivation of ASCs from farm pig as an alternative for the isolation and cultivation of ASCs from minipigs, which require strictly controlled maintenance conditions and a more expensive process.

A new instrument for kinetics and branching ratio studies of gas phase collisional processes at very low temperatures.

A new instrument dedicated to the kinetic study of low-temperature gas phase neutral-neutral reactions, including clustering processes, is presented. It combines a supersonic flow reactor with vacuum ultra-violet synchrotron photoionization time-of-flight mass spectrometry. A photoion-photoelectron coincidence detection scheme has been adopted to optimize the particle counting efficiency. The characteristics of the instrument are detailed along with its capabilities illustrated through a few results obtained at low temperatures (<100 K) including a photoionization spectrum of n-butane, the detection of formic acid dimer formation, and the observation of diacetylene molecules formed by the reaction between the C2H radical and C2H2.

Morphometry of the aortic arch and its branches. A computed tomography angiography-based study.

BACKGROUND: The current study aims to determine the prevalence of variations of the aortic arch using computed tomography angiography (CTA), as well as morphometries and gender correlations. MATERIALS AND METHODS: A retrospective, transverse, observational and descriptive study of 220 CTA was performed. The branching pattern, most cranial vertebral level of the aortic arch, area of the proximal, middle and distal segments of the arch, area of each branch, and the path of atypical arteries were recorded. Results were analysed and stratified by gender. RESULTS: The typical aortic arch branching pattern was present in 77.7% without statistical significance between genders. The most common variant was a two-branch pattern with a common trunk and a left subclavian (13.6%), followed by a typical branching pattern with an added left vertebral artery (7.3%). T3 was the most frequent cranial level (32.3%), followed by T2-T3 (26.8%), and T3-T4 (23.2%). The mean areas of the aortic arch were 685.5 ± 183.9, 476.1 ± 124.1, and 445.0 ± 145.1 mm2 for the proximal, middle and distal segments, with statistical difference between men and women in the middle and distal segments. Three paths of atypical arteries were identified: bifurcated vertebral artery (0.5%), aberrant right subclavian artery (0.5%), and left subclavian ostium obstruction (0.5%). CONCLUSIONS: Mexican population has one of the highest prevalence of variations in the aortic arch branching pattern. The high probability of finding these should be taken into consideration when assessing patients. A standardised classification method would contemplate future un-reported findings, without causing confusion by the different numbers assigned by each author.

Selective identification of cyclopentaring-fused PAHs and side-substituted PAHs in a low pressure premixed sooting flame by photoelectron photoion coincidence spectroscopy.

This work reports on the selective on-line identification of polycyclic aromatic hydrocarbons (PAHs) formed in a low-pressure methane sooting flame, carried out using the double imaging Photoelectron Photoion Coincidence Spectroscopy method (i2PEPICO) on the DESIRS VUV beamline at the synchrotron SOLEIL. Generally, this work demonstrates the capabilities of the i2PEPICO method to identify PAHs in sooting flames, and in particular to distinguish cyclopentaring-fused PAHs (CP-PAHs) and side-substituted PAHs from their benzenoid isomers. Experimental threshold photoelectron spectra of four CP-PAHs: acenapthylene (C12H8, 152 m/z), acenaphtene (C12H10, 154 m/z), fluoranthene (C16H10, 202 m/z) and benzo(ghi)fluoranthene (C18H10, 226 m/z) are also reported for the first time.

Evidence-based algorithm for the management of acute traumatic retrobulbar haemorrhage.

Retrobulbar haemorrhage (RBH) is a potentially blinding consequence of craniofacial trauma, but timely ophthalmic evaluation is difficult to obtain in some settings and clear standards for canthotomy/cantholysis are lacking. We have sought to develop an algorithm to identify vision-threatening traumatic RBH that requires emergent decompression. We retrospectively reviewed 42 consecutive consultations for RBH at a level-one trauma centre. Charts and imaging studies were analysed with attention to mechanism of injury, comorbid trauma, and ophthalmic findings. A total of 22 eyes were observed without intervention, 13 were treated pharmacologically, and seven by emergent canthotomy/cantholysis. No differences in standard trauma metrics were found among these groups. Lid oedema, ecchymosis, chemosis, subconjunctival haemorrhage, and ocular motility also failed to correlate with a need for surgical intervention. "Tight" eyelids (p<0.001), unilateral proptosis (p<0.001), and relative afferent pupillary defect (RAPD; p=0.029), however, all related to a need for canthotomy/cantholysis (Fisher's exact test). Tenting of the globe, which was the only radiographic finding to predict the need for surgery, was seen in just two of the seven cases that required decompression. Many of the traditionally emphasised clinical signs therefore fail to identify cases of RBH that require decompression. Our data support a simple three-factor decision tool. These are: relative proptosis, eyelids that are difficult to open with finger pressure, and presence of an RAPD in the traumatised eye. If all three are noted or if the patient has proptosis and tight lids in the absence of a large preseptal haematoma, he/she is likely to need surgical decompression. Tenting of the globe on computed tomography (CT), while a relatively rare finding, should also alert the physician of the need for intervention.

Photoionization of C4H5 Isomers.

Single-photon, photoelectron-photoion coincidence spectroscopy is used to record the mass-selected ion spectra and slow photoelectron spectra of C4H5 radicals produced by the abstraction of hydrogen atoms from three C4H6 precursors by fluorine atoms generated by a microwave discharge. Three different C4H5 isomers are identified, with the relative abundances depending on the nature of the precursor (1-butyne, 1,2-butadiene, and 1,3-butadiene). The results are compared with our previous work using 2-butyne as a precursor [Hrodmarsson, H. R. J. Phys. Chem. A 2019, 123, 1521-1528]. The slow photoelectron spectra provide new information on the three radical isomers that is in good agreement with previous experimental and theoretical results [Lang, M. J. Phys. Chem. A 2015, 119, 3995-4000; Hansen, N. J. Phys. Chem. A 2006, 110, 3670-3678]. The energy scans of the C4H5 photoionization signal are recorded with substantially better resolution and signal-to-noise ratio than those in earlier work, allowing the observation of autoionizing resonances based on excited states of the C4H5 cation. Photoelectron images recorded at several energies are also reported, providing insight into the decay processes of these excited states. Finally, in contrast to the earlier work using 2-butyne as a precursor, where H-atom abstraction was the only observed process, F- and H-atom additions to the present precursors are also observed through the detection of C4H6F, C4H5F, and C4H7.

Photoelectron spectroscopy of boron-containing reactive intermediates using synchrotron radiation: BH2, BH, and BF.

Mass selected slow photoelectron spectra (SPES) of three boron-containing reactive species, BH2, BH, and BF were recorded by double imaging photoion-photoelectron coincidence spectroscopy (i2PEPICO) using synchrotron radiation. All species were generated in a flow reactor from the H-abstraction of B2H6 by F atoms created in a F2 microwave discharge. The spectrum of BH2+ exhibits a long bending mode progression with a 970 cm-1 spacing due to the large geometry change from bent to linear upon ionization. Its ionization energy was determined as 8.12 ± 0.02 eV. For BH, photoionisation from both X1Σ+ singlet and a3Π triplet state was observed, permitting the experimental determination of the singlet/triplet gap (ΔEST) from the observed IE's of 9.82 eV and 8.48 eV. In addition, a threshold photoelectron spectrum of BF was recorded, which leads to an IE of 11.11 eV and an improved value for νBF+ of 1690 cm-1. All spectra were simulated by calculating Franck-Condon factors from optimised structures based on quantum chemical calculations.

Quantifying the photoionization cross section of the hydroxyl radical.

The hydroxyl free radical, OH, is one of the most important radicals in atmospheric and interstellar chemistry, and its cation plays a role in the reactions leading to H2O formation. Knowledge of the photoionization efficiency of the OH radical is crucial to properly model the water photochemical cycle of atmospheres and astrophysical objects. Using a gas-phase radical source based on a single H-abstraction reaction combined with a photoelectron/photoion imaging coincidence spectrometer coupled with synchrotron radiation, we recorded the OH+ photoion yield over the 12.6-15 eV energy range, and we set it to an absolute cross section scale using an absolute point measurement performed at 13.8 eV: σOH ion=9.0±2.7 Mb. The resulting cross section values differ by approximately a factor 2 from the recent measurement of Dodson et al. [J. Chem. Phys. 148, 184302 (2018)] performed with a different radical source, which is somewhat greater than the combined uncertainties of the measurements. This finding underlines the need for further investigations of this cross section.

Valence-Shell Photoionization of C4H5: The 2-Butyn-1-yl Radical.

We present new high-resolution data on the photoionization of the 2-butyn-1-yl radical (CH3C≡C-•CH2) formed by H atom abstraction from 2-butyne by F atoms. The spectra were recorded from 7.7 to 11 eV by using double-imaging, photoelectron-photoion coincidence spectroscopy, which allows the unambiguous correlation of photoelectron data and the mass of the species. The photoionization spectrum shows significant resonant autoionizing structure converging to excited states of the C4H5+ cation, similar to what is observed in the closely related propargyl radical (HC≡C-•CH2). The threshold photoelectron spectrum, obtained with a resolution of 17 meV, is also reported. This spectrum is consistent with previous measurements of the first photoionization band but has been extended to higher energy to allow the observation of bands corresponding to excited electronic states of the ion. A refined value of the adiabatic ionization energy is extracted: IE(C4H5) = 7.93 ± 0.01 eV. A determination of the absolute photoionization cross section of the 2-butyn-1-yl radical at 9.7 eV is also reported: σion(C4H5) = 6.1 ± 1.8 Mb.

Experimental and theoretical threshold photoelectron spectra of methylene.

The threshold photoelectron spectrum of methylene (CH2), produced by consecutive H atom abstractions on methane, has been recorded using synchrotron radiation. The experimental spectrum spans the region of the X + 2Π u ← X 3 B 1 ionizing transition. It is modeled starting from ab initio bending potentials and using the bending approach introduced by Coudert et al. [J. Chem. Phys. 148, 054302 (2018)] accounting for the quasilinearity of CH2 and the strong Renner-Teller interaction in CH 2 + . This first calculation yields a theoretical threshold photoelectron spectrum which is in moderate agreement with the experimental one. A more accurate approach treating the three vibrational modes is developed for computing the threshold photoelectron spectrum of triatomic C 2 v molecules. This new treatment is tested modeling the already measured threshold photoelectron spectrum of the X + 2Π u ← X 1 A 1 ionizing transition of the water molecule. The threshold photoelectron spectrum of CH2 computed with the new approach compares more favorably with the experimental spectrum and yields an adiabatic ionization potential of 10.386(6) eV.