RESUMO
The interaction between nitrogen-doped graphene defects (N3V1 and N4V2 pyridinic, and N3V1 and N3V3 pyrrolic) and benzene have been investigated by applying density functional theory (DFT), together with the vdW-DF correction. We discovered that only the N3V3 pyrrolic defect is a reactive site (6π-component), forming a cycloadduct with benzene (4π-component) that has energy barriers below 154.38 kJ mol-1 (1.60 eV). The conduction and valence bands (HOMO and LUMO) for N3V3 form a degenerate pair of orbitals at the gamma point, with the same ionization potential (IP) and electron affinity (EA). Likewise, inspection of the orbital symmetries for both systems confirms that these must undergo concerted reactions based on the Woodward and Hoffmann principles of orbital symmetry, with the appropriate orbital occupancies. This is the first time that substitutionally doped graphene has been demonstrated to participate as a 6π-component for cycloaddition reactions with benzene.
RESUMO
Resumen: La lesión del nervio axilar (o circunflejo) aislada es poco frecuente, ésta suele presentarse asociada a una lesión del plexo braquial. En nuestra institución, en un período comprendido entre los años 2015-2017, se ha observado una frecuencia de sólo 0.4% de esta lesión. Con el presente reporte de caso se resalta la relación de la luxación de hombro con lesión del nervio axilar aislada. Caso clínico: Masculino de 31 años de edad, con trauma en hombro derecho, secundario a caída de su propia altura en accidente laboral. Radiografía de ingreso de hombro derecho muestra luxación anteroinferior de articulación glenohumeral, asociada a fractura de troquiter. Es intervenido quirúrgicamente, con reducción cerrada de articulación glenohumeral y osteosíntesis de troquiter. Posterior a ello, el paciente presenta atrofia marcada del deltoides, se ordena electromiografía que evidencia lesión completa del nervio axilar sin reinervación.
Abstract: Isolated lesion of the axillary (or circumflex) nerve is infrequent, this is usually associated with a brachial plexus injury. In our institution, in a period comprised between the years 2015-2017, a frequency of only 0.4% of this injury has been observed. Clinical case: Male patient of 31 years of age, with trauma in the right shoulder, caused by fall of his own height in work accident. The admission graph of the right shoulder shows anterior inferior dislocation of the glenohumeral joint, associated with a greater tubercle fracture. He underwent surgery, with closed reduction of the glenohumeral joint and osteosynthesis of the greater tubercle. The patient later presents marked atrophy of the deltoid, electromyography is ordered that shows complete lesion of the axillary nerve without reinnervation.
Assuntos
Humanos , Masculino , Adulto , Luxação do Ombro , Articulação do Ombro , Plexo Braquial , Neuropatias do Plexo Braquial , Ombro , Lesões do OmbroRESUMO
An electrochemical impedimetric immunosensor was developed for the detection of the neuropeptide Corticotropin Releasing Hormone (CRH) based on the immobilization of half-antibody fragments on gold nanoparticles (AuNp). Then, the optimal conditions for the obtainment of AuNp through electroplating on a bare gold electrode were studied. The results showed that the obtainment of AuNp at a fixed potential of -0.2â¯V for 330â¯s, at 80⯰C and 2·10-3 mol·L-1 of HAuCl4 generates an adequate nanostructured surface and is a highly reproducible method. Also, the optimal conditions for immobilizing the half-antibody on AuNp were studied. The interaction of the CRH with the recognition layer of the immobilized half-antibody on the nanostructured surface was carried out by incubation at 4⯰C for 2â¯h. A dissolution of [Fe(CN)6]4-/[Fe(CN)6]3- as a redox probe was used to study the electrochemical responses of the nanostructured surface and the immobilization processes of the half-antibody and detection of CRH, using cyclic voltammetry and electrochemical impedance spectroscopy. An immunosensor was obtained for the specific detection of CRH, within a range of 10.0-80.0⯵gâ¯mL-1, with a limit of detection of 2.7⯵gâ¯mL-1 and a limit of quantification of 9.2⯵gâ¯mL-1. Additionally, the association constant between the CRH and the immobilized half-antibody was calculated at 1.96·105 M-1.
Assuntos
Técnicas Biossensoriais , Hormônio Liberador da Corticotropina/isolamento & purificação , Espectroscopia Dielétrica , Fragmentos de Imunoglobulinas/química , Anticorpos/química , Anticorpos/imunologia , Anticorpos Imobilizados/química , Hormônio Liberador da Corticotropina/química , Hormônio Liberador da Corticotropina/imunologia , Técnicas Eletroquímicas , Humanos , Imunoensaio , Fragmentos de Imunoglobulinas/imunologia , Limite de Detecção , Nanopartículas Metálicas/química , NanoestruturasRESUMO
Isolated lesion of the axillary (or circumflex) nerve is infrequent, this is usually associated with a brachial plexus injury. In our institution, in a period comprised between the years 2015-2017, a frequency of only 0.4% of this injury has been observed. Clinical case: Male patient of 31 years of age, with trauma in the right shoulder, caused by fall of his own height in work accident. The admission graph of the right shoulder shows anterior inferior dislocation of the glenohumeral joint, associated with a greater tubercle fracture. He underwent surgery, with closed reduction of the glenohumeral joint and osteosynthesis of the greater tubercle. The patient later presents marked atrophy of the deltoid, electromyography is ordered that shows complete lesion of the axillary nerve without reinnervation.
La lesión del nervio axilar (o circunflejo) aislada es poco frecuente, ésta suele presentarse asociada a una lesión del plexo braquial. En nuestra institución, en un período comprendido entre los años 2015-2017, se ha observado una frecuencia de sólo 0.4% de esta lesión. Con el presente reporte de caso se resalta la relación de la luxación de hombro con lesión del nervio axilar aislada. Caso clínico: Masculino de 31 años de edad, con trauma en hombro derecho, secundario a caída de su propia altura en accidente laboral. Radiografía de ingreso de hombro derecho muestra luxación anteroinferior de articulación glenohumeral, asociada a fractura de troquiter. Es intervenido quirúrgicamente, con reducción cerrada de articulación glenohumeral y osteosíntesis de troquiter. Posterior a ello, el paciente presenta atrofia marcada del deltoides, se ordena electromiografía que evidencia lesión completa del nervio axilar sin reinervación.
Assuntos
Neuropatias do Plexo Braquial , Plexo Braquial , Luxação do Ombro , Articulação do Ombro , Adulto , Humanos , Masculino , Ombro , Lesões do OmbroRESUMO
Pathogenesis of cryptococcosis in the central nervous system (CNS) is a topic of ongoing research, including the mechanisms by which this fungus invades and infects the brain. Astrocytes, the most common CNS cells, play a fundamental role in the local immune response. Astrocytes might participate in cryptococcosis either as a host or by responding to fungal antigens. To determine the infectivity of Cryptococcus neoformans var. grubii and Cryptococcus gattii in a human astrocytoma cell line and the induction of major histocompatibility complex (MHC) molecules. A glioblastoma cell line was infected with C. neoformans var. grubii and C. gattii blastoconidia labelled with FUN-1 fluorescent stain. The percentage of infection and expression of HLA class I and II molecules were determined by flow cytometry. The interactions between the fungi and cells were observed by fluorescence microscopy. There was no difference between C. neoformans var. grubii and C. gattii in the percentage infection, but C. neoformans var. grubii induced higher expression of HLA class II than C. gattii. More blastoconidia were recovered from C. neoformans-infected cells than from C. gattii infected cells. Cryptococcus neoformans var. grubii may have different virulence mechanisms that allow its survival in human glia-derived cells.
Assuntos
Astrócitos/microbiologia , Cryptococcus gattii/crescimento & desenvolvimento , Cryptococcus neoformans/crescimento & desenvolvimento , Linhagem Celular , Citometria de Fluxo , Antígenos HLA/análise , Humanos , Viabilidade Microbiana , Microscopia de FluorescênciaRESUMO
Endocarditis associated with dialysis catheter is a disease that must be suspected in every patient with hemodialysis who develops fever. Multiple valve disease is a severe complication of endocarditis that needs to be managed in a different way. There is very limited data for treatment and every case must be considered individually. We present a patient with this complication and describe the medical treatment and surgical management. We report the case of a 15-year-old patient with acute renal failure that develops trivalvular endocarditis after the hemodialysis catheter was placed, with multiple positive blood culture for Staphylococcus aureus. Transesophageal echocardiography was done and aortic and tricuspid valvular vegetations and mitral insufficiency were reported. Patient was successfully treated by surgery on the three valves, including aortic valve replacement. There is limited data about the appropriate treatment for multiple valvular endocarditis; it is important to consider this complication in the setting of hemodialysis patients that develop endocarditis and, despite the appropriate treatment, have a torpid evolution. In countries where endovenous drug abuse is uncommon, right sided endocarditis is commonly associated with vascular catheters. Aggressive surgical management should be the treatment of choice in these kinds of patients.
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Recently it has been reported that prolactin (PRL) exerts a neuroprotective effect against excitotoxicity in hippocampus in the rat in vivo models. However, the exact mechanism by which PRL mediates this effect is not completely understood. The aim of our study was to assess whether prolactin exerts neuroprotection against excitotoxicity in an in vitro model using primary cell cultures of hippocampal neurons, and to determine whether this effect is mediated via the prolactin receptor (PRLR). Primary cell cultures of rat hippocampal neurons were used in all experiments, gene expression was evaluated by RT-qPCR, and protein expression was assessed by Western blot analysis and immunocytochemistry. Cell viability was assessed by using the MTT method. The results demonstrated that PRL treatment of neurons from primary cultures did not modify cell viability, but that it exerted a neuroprotective effect, with cells treated with PRL showing a significant increase of viability after glutamate (Glu)--induced excitotoxicity as compared with neurons treated with Glu alone. Cultured neurons expressed mRNA for both PRL and its receptor (PRLR), and both PRL and PRLR expression levels changed after the excitotoxic insult. Interestingly, the PRLR protein was detected as two main isoforms of 100 and 40 kDa as compared with that expressed in hypothalamic cells, which was present only as a 30 kDa variant. On the other hand, PRL was not detected in neuron cultures, either by western blot or by immunohistochemistry. Neuroprotection induced by PRL was significantly blocked by specific oligonucleotides against PRLR, thus suggesting that the PRL role is mediated by its receptor expressed in these neurons. The overall results indicated that PRL induces neuroprotection in neurons from primary cell cultures.
Assuntos
Hipocampo/citologia , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Prolactina/farmacologia , Receptores da Prolactina/metabolismo , Análise de Variância , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Embrião de Mamíferos , Agonistas de Aminoácidos Excitatórios/toxicidade , Regulação da Expressão Gênica/efeitos dos fármacos , Ácido Glutâmico/toxicidade , Oligonucleotídeos/farmacologia , Prolactina/genética , Prolactina/metabolismo , RNA Mensageiro/metabolismo , Ratos , Receptores da Prolactina/genéticaRESUMO
En años recientes la sonificación de electroencefalogramas (EEG) ha sido utilizada como una alternativa para analizar señales cerebrales al convertir el EEG en audio. En este trabajo se aplica la sonificación a señales de EEG durante el habla imaginada o habla no pronunciada, con el objetivo de mejorar la clasificación automática de 5 palabras del idioma español. Para comprobarlo, se procesó la señal cerebral de 27 sujetos sanos. Estas señales fueron sonificadas para después extraer características con dos métodos diferentes: la transformada Wavelet discreta (DWT); y los coeficientes cepstrales en la escala de Mel (MFCC). Éste último comúnmente utilizado en tareas de reconocimiento de voz. Para clasificar las señales se aplicaron tres algoritmos distintos de clasificación Naive Bayes (NB), Máquina de vectores de soporte (SVM) y Random Forest (RF). Se obtuvieron resultados usando los 4 canales más cercanos a las áreas de lenguaje de Broca y Wernicke, así como también los 14 canales del dispositivo EEG utilizado. Los porcentajes de exactitud promedio para los 27 sujetos en los dos conjuntos de 4 y 14 canales usando sonificación de EEG fueron de 55.83% y 64.14% respectivamente, con lo que se logró mejorar ligeramente los porcentajes de clasificación de las palabras imaginadas respecto a no utilizar sonificación.
In recent years sonification of electroencephalograms (EEG) has been used as an alternative to analyze brain signals after converting EEG to audio. In this paper we applied the sonification to EEG signals during the imagined speech or unspoken speech, with the aim of improving the automatic classification of 5 words of Spanish. To check this, the brain signals of 27 healthy subjects were processed. These sonificated signals were processed to extract features with two different methods: discrete wavelet transform (DWT); and the Mel-frequencies cepstral coefficients (MFCC). The latter commonly used in speech recognition tasks. To classify the signals three different classification algorithms Naive Bayes (NB), Support Vector Machine (SVM) and Random Forest (RF) were applied. Results were obtained using the 4 channels closest to the language areas of Broca and Wernicke, as well as the 14 channels of the EEG device used. The percentages of average accuracy for the 27 subjects in the two sets of 4 and 14 channels using EEG sonification were 55.83% and 64.14% respectively, which are improvements in the classification rates of the imagined words compared with a scheme without sonification.
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Antecedentes: La utilización de torniquete neumático (TN) en la artroplastía total de rodilla (ATR) ha sido tema de controversia, describiendo ventajas, desventajas y complicaciones asociadas. Con la finalidad de evaluar los beneficios de su utilización se estudió el tiempo quirúrgico, volumen de sangrado transquirúrgico, postquirúrgico y total, así como los valores de hemoglobina y hematocrito pre y postquirúrgicos de pacientes a los que se les realizo ATR primaria utilizando TN y se compararon con un grupo control. Material y métodos: Se realizó un análisis retrospectivo de expedientes clínicos de casos sometidos a ATR; en apego a los criterios de inclusión se obtuvo un grupo de estudio (n = 19) y control (n = 19) según la utilización o no de TN. Se compararon el tiempo quirúrgico, el sangrado transquirúrgico y postquirúrgico así como el sangrado total; valores de hemoglobina y hematocrito iniciales y finales. Resultados: Se obtuvieron diferencias significativas a favor del grupo en quienes se utilizó TN en 7 de 8 variables estudiadas, siendo el tiempo empleado (t = 2.08 p < 0.050); sangrado transquirúrgico (t = -6.44, p < 0.010); postquirúrgico (t = -2.170 p < 0.050) y total (t = /7.52, p < 0.010), las más relevantes. Conclusiones: Los resultados mostraron que los sujetos a quienes se les aplicó TN durante la ATR requirieron menos tiempo quirúrgico y que el sangrado total, trans y postquirúrgico, así como la perdida sanguínea calculada fueron menores que los controles. Mayores conjeturas sobre los beneficios del TN ameritan la realización de más investigaciones prospectivas.
Background: The use of the pneumatic tourniquet (PT) in total knee arthroplasty (TKA) has been controversial; its advantages, disadvantages and associated complications have been described. In order to assess its benefits we analyzed operative time; intraoperative, postoperative and total bleeding volume, as well as pre- and postoperative hemoglobin and hematocrit values in patients who had undergone primary TKA using the PT, and they were compared with a control group. Material and methods: A retrospective analysis of the clinical records of cases who underwent TKA was conducted. Based on the inclusion criteria and the use or non-use of PT, two groups were formed: a study group (n = 19) and a control group (n = 19). The following variables were compared: operative time, intra and postoperative bleeding and total bleeding; initial and final hemoglobin and hematocrit values. Results: Significant differences in favor of the group with PT use were obtained in 7 out of the 8 variables studied. The most relevant ones were operative time (t = 2.08 p < 0.050); intraoperative bleeding (t = -6.44, p < 0.010); postoperative bleeding (t = -2.170 p < 0.050) and total bleeding (t = /7.52, p < 0.010). Conclusions: The results showed that patients in whom PT was used during TKA had a shorter operative time, and their total, intra- and postoperative bleeding and the estimated blood loss were lower than in controls. Additional suppositions on the benefits of PT warrant the conduction of more prospective research studies.
Assuntos
Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Artroplastia do Joelho/métodos , Perda Sanguínea Cirúrgica , Hemorragia Pós-Operatória/epidemiologia , Torniquetes , Hematócrito , Hemoglobinas/metabolismo , Duração da Cirurgia , Estudos RetrospectivosRESUMO
BACKGROUND: The use of the pneumatic tourniquet (PT) in total knee arthroplasty (TKA) has been controversial; its advantages, disadvantages and associated complications have been described. In order to assess its benefits we analyzed operative time; intraoperative, postoperative and total bleeding volume, as well as pre- and postoperative hemoglobin and hematocrit values in patients who had undergone primary TKA using the PT, and they were compared with a control group. MATERIAL AND METHODS: A retrospective analysis of the clinical records of cases who underwent TKA was conducted. Based on the inclusion criteria and the use or nonuse of PT, two groups were formed: a study group (n=19) and a control group (n=19). The following variables were compared: operative time, intra and postoperative bleeding and total bleeding; initial and final hemoglobin and hematocrit values. RESULTS: Significant differences in favor of the group with PT use were obtained in 7 out of the 8 variables studied. The most relevant ones were operative time (t = 2.08 p < 0.050); intraoperative bleeding (t = -6.44, p < 0.010); postoperative bleeding (t = -2.170 p < 0.050) and total bleeding (t = /7.52, p < 0.010). CONCLUSIONS: The results showed that patients in whom PT was used during TKA had a shorter operative time, and their total, intra- and postoperative bleeding and the estimated, blood loss were lower than in controls. Additional suppositions on the benefits of PT warrant the conduction'of more prospective research studies.