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Multivalency in lectins plays a pivotal role in influencing glycan cross-linking, thereby affecting lectin functionality. This multivalency can be achieved through oligomerization, the presence of tandemly repeated carbohydrate recognition domains, or a combination of both. Unlike lectins that rely on multiple factors for the oligomerization of identical monomers, tandem-repeat lectins inherently possess multivalency, independent of this complex process. The repeat domains, although not identical, display slightly distinct specificities within a predetermined geometry, enhancing specificity, affinity, avidity and even oligomerization. Despite the recognition of this structural characteristic in recently discovered lectins by numerous studies, a unified criterion to define tandem-repeat lectins is still necessary. We suggest defining them multivalent lectins with intrachain tandem repeats corresponding to carbohydrate recognition domains, independent of oligomerization. This systematic review examines the folding and phyletic diversity of tandem-repeat lectins and refers to relevant literature. Our study categorizes all lectins with tandemly repeated carbohydrate recognition domains into nine distinct folding classes associated with specific biological functions. Our findings provide a comprehensive description and analysis of tandem-repeat lectins in terms of their functions and structural features. Our exploration of phyletic and functional diversity has revealed previously undocumented tandem-repeat lectins. We propose research directions aimed at enhancing our understanding of the origins of tandem-repeat lectin and fostering the development of medical and biotechnological applications, notably in the design of artificial sugars and neolectins.
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Lectinas , Sequências de Repetição em Tandem , Animais , Humanos , Lectinas/química , Lectinas/metabolismoRESUMO
OBJECTIVE: Tracheal intubation in cardiac surgery patients has a higher incidence of difficult laryngoscopic views compared with patients undergoing other types of surgery. The authors hypothesized that using the McGrath Mac videolaryngoscope as the first intubation option for cardiac surgery patients improves the percentage of patients with "easy intubation" compared with using a direct Macintosh laryngoscope. DESIGN: A prospective, observational, before-after study. SETTING: At a tertiary-care hospital. PARTICIPANTS: One thousand one hundred nine patients undergoing cardiac surgery. INTERVENTION: Consecutive patients undergoing cardiac surgery were intubated using, as the first option, a Macintosh laryngoscope (preinterventional phase) or a McGrath Mac videolaryngoscope (interventional phase). MEASUREMENTS AND MAIN RESULTS: The main objective was to assess whether the use of the McGrath videolaryngoscope, as the first intubation option, improves the percentage of patients with "easy intubation," defined as successful intubation on the first attempt, modified Cormack-Lehane grades of I or IIa, and the absence of the need for adjuvant airway devices. A total of 1,109 patients were included, 801 in the noninterventional phase and 308 in the interventional phase. The incidence of "easy intubation" was 93% in the interventional phase versus 78% in the noninterventional phase (p < 0.001). First-success-rate intubation was higher in the interventional phase (304/308; 98.7%) compared with the noninterventional phase (754/801, 94.1%; p = 0.005). Intubation in the interventional phase showed decreases in the incidence of difficult laryngoscopy (12/308 [3.9%] v 157/801 [19.6%]; p < 0.001), as well as moderate or difficult intubation (5/308 [1.6%] v 57/801 [7.1%]; p < 0.001). CONCLUSIONS: The use of the McGrath videolaryngoscope as the first intubation option for tracheal intubation in cardiac surgery improves the percentage of patients with "easy" intubation," increasing glottic view and first-success-rate intubation and decreasing the incidence of moderate or difficult intubation.
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Procedimentos Cirúrgicos Cardíacos , Intubação Intratraqueal , Laringoscópios , Laringoscopia , Gravação em Vídeo , Humanos , Intubação Intratraqueal/instrumentação , Intubação Intratraqueal/métodos , Estudos Prospectivos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Laringoscopia/métodos , Laringoscopia/instrumentação , Procedimentos Cirúrgicos Cardíacos/métodos , Procedimentos Cirúrgicos Cardíacos/instrumentação , Gravação em Vídeo/métodos , Salas CirúrgicasRESUMO
BACKGROUND: Partial-thickness rotator cuff tears treated with an isolated bioinductive repair (IBR) in lieu of a completion-and-repair have shown complete healing. This treatment option is afforded by the remaining tendon's structural integrity, which is similar to that present in small/medium full-thickness tears (FTTs) when the rotator cable remains intact. This randomized controlled trial (RCT) investigated whether an IBR for small/medium full-thickness tears resulted in superior healing and patient-reported outcomes (PROs) compared with a sutured repair. METHODS: This prospective, double blinded (patients and outcome assessors), single-center randomized controlled trial enrolled patients ≥18 years with a small/medium (≤2.5 cm) full thickness supraspinatus tear and intact rotator cable. Patients were randomized and blinded to arthroscopic transosseous-equivalent repair (control, n = 30) or IBR (n = 30). The primary outcome was tendon quality on biopsy at 6 months. Secondary outcomes were PROs (American Shoulder and Elbow Surgeons [ASES], Constant-Murley Shoulder [CMS], and pain visual analogue scale scores) and tendon thickness and healing measured via MRI at 6, 12, and 24 months; satisfaction at 12 and 24 months; and time to return to work. RESULTS: Baseline demographic, tear, and surgical characteristics were comparable between the groups (IBR: mean age, 54.2 years, 14 male; control: mean age, 56.4 years, 16 male). Measured via a 6-month biopsy, highly organized, parallel bundles of collagen, without inflammation, were present in all IBR patients, whereas poorly organized, nonparallel collagen fibers were present in 24/30 (80%) of control patients (P < .0001), with 28/30 having minimal to mild inflammation. The increase in tendon thickness measured via MRI at 6 months from baseline was greater in the IBR group (2.0 mm) than in the control group (0.8 mm) (P < .0001). All IBR patients had 100% healing on MRI at 12 and 24 months. Compared with the control group, the IBR group had higher American Shoulder and Elbow Surgeons and Constant-Murley Shoulder scores at each evaluation, less pain at 6 and 12 months, and greater satisfaction at 12 and 24 months (P < .0003). The IBR group returned to work significantly faster (median 90 days [IQR, 25] vs. median 163.5 days [IQR, 24]; P < .0001) than the control group. CONCLUSION: Compared with a sutured repair, the IBR treatment resulted in superior tendon quality, patient outcomes, satisfaction, and return to work. The IBR enabled a robust healing response evident through MRI and biopsy evaluation, demonstrating superior tendon quality and healing.
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Artroscopia , Lesões do Manguito Rotador , Técnicas de Sutura , Humanos , Lesões do Manguito Rotador/cirurgia , Método Duplo-Cego , Masculino , Pessoa de Meia-Idade , Feminino , Artroscopia/métodos , Estudos Prospectivos , Idoso , Resultado do Tratamento , Manguito Rotador/cirurgia , Medidas de Resultados Relatados pelo Paciente , Cicatrização , Imageamento por Ressonância MagnéticaRESUMO
Migraine is a highly prevalent neurological disorder. Among the risk factors identified, psychiatric comorbidities, such as depression, seem to play an important role in its onset and clinical course. Patients with migraine are 2.5 times more likely to develop a depressive disorder; this risk becomes even higher in patients suffering from chronic migraine or migraine with aura. This relationship is bidirectional, since depression also predicts an earlier/worse onset of migraine, increasing the risk of migraine chronicity and, consequently, requiring a higher healthcare expenditure compared to migraine alone. All these data suggest that migraine and depression may share overlapping biological mechanisms. Herein, this review explores this topic in further detail: firstly, by introducing the common epidemiological and risk factors for this comorbidity; secondly, by focusing on providing the cumulative evidence of common biological aspects, with a particular emphasis on the serotoninergic system, neuropeptides such as calcitonin-gene-related peptide (CGRP), pituitary adenylate cyclase-activating polypeptide (PACAP), substance P, neuropeptide Y and orexins, sexual hormones, and the immune system; lastly, by remarking on the future challenges required to elucidate the etiopathological mechanisms of migraine and depression and providing updated information regarding new key targets for the pharmacological treatment of these clinical entities.
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Depressão , Transtornos de Enxaqueca , Humanos , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/uso terapêutico , Transtornos de Enxaqueca/tratamento farmacológico , Transtornos de Enxaqueca/etiologia , Peptídeo Relacionado com Gene de Calcitonina , Neuropeptídeo YRESUMO
In this work, we present a new family of Zone Plates (ZPs) designed using the self-generating Kolakoski sequence. The focusing and imaging properties of these aperiodic diffractive lenses coined Kolakoski Zone Plates (KZPs) are extensively studied. It is shown that under monochromatic plane-wave illumination, a KZP produces two main foci of the same intensity along the axial axis. Moreover, one of the corresponding focal lengths is double the other, property correlated with the involved aperiodic sequence. This distinctive optical characteristic is experimentally confirmed. We have also obtained the first images provided by these bifocal new diffractive lenses.
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As the uncontrolled entry of calcium ions (Ca2+) through plasmalemmal calcium channels is a cell death trigger, the conjecture is here raised that mitigating such an excess of Ca2+ entry should rescue from death the vulnerable neurons in neurodegenerative diseases (NDDs). However, this supposition has failed in some clinical trials (CTs). Thus, a recent CT tested whether isradipine, a blocker of the Cav1 subtype of voltage-operated calcium channels (VOCCs), exerted a benefit in patients with Parkinson's disease (PD); however, outcomes were negative. This is one more of the hundreds of CTs done under the principle of one-drug-one-target, that have failed in Alzheimer's disease (AD) and other NDDs during the last three decades. As there are myriad calcium channels to let Ca2+ ions gain the cell cytosol, it seems reasonable to predict that blockade of Ca2+ entry through a single channel may not be capable of preventing the Ca2+ flood of cells by the uncontrolled Ca2+ entry. Furthermore, as Ca2+ signaling is involved in the regulation of myriad functions in different cell types, it seems also reasonable to guess that a therapy should be more efficient by targeting different cells with various drugs. Here, we propose to mitigate Ca2+ entry by the simultaneous partial blockade of three quite different subtypes of plasmalemmal calcium channels that is, the Cav1 subtype of VOCCs, the Orai1 store-operated calcium channel (SOCC), and the purinergic P2X7 calcium channel. All three channels are expressed in both microglia and neurons. Thus, by targeting the three channels with a combination of three drug blockers we expect favorable changes in some of the pathogenic features of NDDs, namely (i) to mitigate Ca2+ entry into microglia; (ii) to decrease the Ca2+-dependent microglia activation; (iii) to decrease the sustained neuroinflammation; (iv) to decrease the uncontrolled Ca2+ entry into neurons; (v) to rescue vulnerable neurons from death; and (vi) to delay disease progression. In this review we discuss the arguments underlying our triad hypothesis in the sense that the combination of three repositioned medicines targeting Cav1, Orai1, and P2X7 calcium channels could boost neuroprotection and delay the progression of AD and other NDDs.
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BACKGROUND: Transesophageal echocardiogram probe insertion in intubated critically ill patients can be difficult, leading to complications, such as gastric bleeding or lesions in the oropharyngeal mucosa. We hypothesised that the use of a videolaryngoscope would facilitate the first attempt at insertion of the transesophageal echocardiogram probe and would decrease the incidence of complications compared to the conventional insertion technique. METHODS: In this clinical trial, patients were randomly assigned the insertion of a transesophageal echocardiogram probe using a videolaryngoscope or conventional technique. The primary outcome was the successful transesophageal echocardiogram probe insertion on the first attempt. The secondary outcomes included total success rate, number of insertion attempts, and incidence of pharyngeal complications. RESULTS: A total of 100 intubated critically ill patients were enrolled. The success rate of transesophageal echocardiogram probe insertion on the first attempt was higher in the videolaryngoscope group than in the conventional group (90% vs. 58%; absolute difference, 32%; 95% CI 16%-48%; p < 0.001). The overall success rate was higher in the videolaryngoscope group than in the conventional group (100% vs. 72%; absolute difference, 28%; 95% CI 16%-40%; p < 0.001). The incidence of pharyngeal mucosal injury was smaller in the videolaryngoscope group than in the conventional group (14% vs. 52%; absolute difference, 38%; 95% CI 21%-55%; p < 0.001). CONCLUSIONS: Our study showed that in intubated critically ill patients required transesophageal echocardiogram, the use of videolaryngoscope resulted in higher successful insertion on the first attempt with lower rate of complications when compared with the conventional insertion technique. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04980976.
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Laringoscópios , Laringoscopia , Humanos , Laringoscopia/efeitos adversos , Laringoscopia/métodos , Ecocardiografia Transesofagiana/efeitos adversos , Ecocardiografia Transesofagiana/métodos , Estado Terminal/terapia , Intubação Intratraqueal/efeitos adversos , Intubação Intratraqueal/métodos , Unidades de Terapia IntensivaRESUMO
BACKGROUND: Recent meta-analyses and randomized studies have shown that among patients with acute ischemic stroke undergoing endovascular thrombectomy, general anesthesia with mechanical ventilation is associated with better functional status compared to local anesthesia and sedation, and they recommend its use. But once the procedure is completed, when is the optimal moment for extubation? Currently, there are no guidelines recommending the optimal moment for extubation. Prolonged mechanical ventilation time could potentially be linked to increased complications such as pneumonia or disturbances in cerebral blood flow due to the vasodilatation produced by most anesthetic drugs. However, premature extubation in a patient who has suffered a stroke could led to complications such as agitation, disorientation, abolished reflexes, sudden fluctuations in blood pressure, alterations in cerebral blood flow, respiratory distress, bronchial aspiration, and the need for reintubation. We therefore designed a randomized study hypothesizing that early compared with delayed extubation is associated with a better functional outcome 3 months after endovascular thrombectomy treatment under general anesthesia for acute ischemic stroke. METHODS: This investigator-initiated, single-center, prospective, parallel, evaluated blinded, superiority, randomized controlled trial will include 178 patients with a proximal occlusion of the anterior circulation treated with successful endovascular thrombectomy (TICI 2b-3) under general anesthesia. Patients will be randomly allocated to receive early (< 6 h) or delayed (6-12 h) extubation after the procedure. The primary outcome measure is functional independence (mRS of 0-2) at 90 days, measured with the modified Rankin Score (mRS), ranging from 0 (no symptoms) to 6 (death). DISCUSSION: This will be the first trial to compare the effect of mechanical ventilation duration (early vs delayed extubation) after satisfactory endovascular thrombectomy for acute ischemic stroke under general anesthesia. TRIAL REGISTRATION: The study protocol was approved April 11, 2023, by the by the Santiago-Lugo Research Ethics Committee (CEI-SL), number 2023/127, and was registered into the clinicaltrials.gov clinical trials registry with No. NCT05847309. Informed consent is required. Participant recruitment begins on April 18, 2023. The results will be submitted for publication in a peer-reviewed journal and presented at one or more scientific conferences.
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Extubação , Anestesia Geral , Procedimentos Endovasculares , AVC Isquêmico , Trombectomia , Humanos , Trombectomia/métodos , Trombectomia/efeitos adversos , Estudos Prospectivos , AVC Isquêmico/fisiopatologia , AVC Isquêmico/cirurgia , AVC Isquêmico/terapia , Procedimentos Endovasculares/métodos , Procedimentos Endovasculares/efeitos adversos , Fatores de Tempo , Resultado do Tratamento , Ensaios Clínicos Controlados Aleatórios como Assunto , Recuperação de Função Fisiológica , Estado Funcional , Estudos de Equivalência como Asunto , Respiração Artificial , MasculinoRESUMO
Introducción. Existe una gran heterogeneidad en los estudios que abordan la efectividad e indicación del tratamiento con ondas de choque (OCH) en la fascitis plantar (FP) respecto a otros tratamientos alternativos. Objetivos. Evaluar la efectividad del tratamiento con OCH en pacientes con FP mediante las evidencias científicas más actuales y evaluar la eficacia de este tratamiento en comparación con otros tipos de terapias también empleadas en el manejo de esta inflamación. Materiales y métodos. Se realizó una búsqueda bibliográfica en las bases de datos PubMed y PEDro con los términos clave "shock wave" y "plantar fasciitis AND shock wave". Se selecciona- ron artículos publicados en español e inglés entre los años 2015 y 2019. Resultados. Tras aplicar los criterios de inclusión y exclusión y luego de eliminar los duplica- dos, se seleccionaron 13 estudios que englobaban una muestra total de 1.220 individuos y comparaban las OCH frente a placebo, OCH con ejercicios, ultrasonoterapia, laserterapia de bajo nivel e infiltración de corticoides y toxina botulínica. Conclusión. Las OCH constituyen un método eficaz y seguro para tratar la FP, siendo más efectivo que la ultrasonoterapia y la infiltración de toxina botulínica, aunque existe controversia en el resto de comparaciones. Su uso se aconseja asociado a un programa de ejercicios; sin embargo, es necesario realizar más estudios sobre esta técnica.
Introduction. There is great heterogeneity in the studies that address the effectiveness and indication of shock wave therapy (SWT) in plantar fasciitis (PF) with respect to other alternative treatments. Objectives. To evaluate the effectiveness of OCH treatment in patients with PF using the most current scientific evidence and to assess the efficacy of this treatment in comparison with other types of therapies also used in the management of this inflammation. Materials and methods. A literature search was performed in the PubMed and PEDro databases with the key terms "shock wave" and "plantar fasciitis AND shock wave". Articles published in Spanish and English between 2015 and 2019 were selected. Results. After applying the inclusion and exclusion criteria and after eliminating duplicates, 13 studies were selected that encompassed a total sample of 1,220 individuals and compared OCH versus placebo, OCH with exercises, ultrasound therapy, low-level laser therapy, and corticosteroid and botulinum toxin infiltration. Conclusion. OCH is an effective and safe method to treat PF, being more effective than ultrasound therapy and botulinum toxin infiltration, although there is controversy in the rest of the comparisons. Its use is recommended in association with an exercise program; however, further studies on this technique are needed.
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Humanos , Masculino , Feminino , Criança , AdolescenteRESUMO
La articulación interfalángica proximal otorga la mayor contribución al arco total de movimiento digital, por lo tanto, la pérdida de movimiento normal de la articulación tiene un impacto considerable en la función y fuerza de agarre. El único método que asegura la preservación a largo plazo de la arquitectura cartilaginosa, así como una curación ósea rápida tras destrucción articular traumática o patológica es la transferencia articular vascularizada. Es definida como un trasplante articular parcial o completo con preservación o restauración inmediata del flujo de sangre. Se presenta el caso de un masculino de 20 años, con antecedente de trauma contuso-cortante en borde cubital de 3er dedo de mano izquierda zona II a quien se realiza cierre primario. Siete meses después a presentó deformidad articular e incapacidad funcional para la flexión de articulación interfalángica proximal. Se realizó procedimiento de reconstrucción articular, mediante transferencia articular vascularizada de 2° dedo del pie derecho. Posteriormente se dio seguimiento a través de consulta externa a las 2, 4, 6 y 8 semanas, 6 meses y 12 meses. A los 6 meses fue sometido a capsulotomía, liberación de placa volar, retiro de placas de osteosíntesis y adelgazamiento de isla cutánea. Se alcanzaron rangos de movimiento pasivo de extensión de 85° y activo de 70°. En base a la experiencia de nuestro centro se demuestra que el uso de transferencia articular en 2 etapas de reconstrucción, se pueden mantener rangos de movimiento tanto activo como pasivo suficiente para una adecuada función.
The proximal interphalangeal joint provides the greatest contribution to the total arc of digital movement, therefore, the loss of normal movement of the joint has a considerable impact on function and grip strength. The only method that ensures the long-term preservation of the cartilaginous architecture, as well as a rapid recovery of traumatic or pathological joint destruction, is vascularized joint transfer. It is defined as a partial or complete partial transplant with preservation or immediate restoration of blood flow. We present the case of a 20-year-old man, with a history of contusive-cutting trauma on the ulnar border of the third finger of the left hand, area II, who underwent primary closure. Seven months after the presentation of the joint and functional disability for proximal interphalangeal joint flexion. A joint reconstruction process was performed, by means of a vascularized joint transfer of the 2nd toe of the right foot. Subsequently, follow-up was carried out through the outpatient clinic at 2, 4, 6 and 8 weeks, 6 months and 12 months. At 6 months he was subjected capsulotomy, volar plate release, osteosynthesis plates removal and cutaneous island thinning. Ranges of passive movement of extension of 85° and active of 70° were reached. Based on the experience of our center, it is shown that the use of the transfer was made in 2 stages of reconstruction, the range of both active and passive movements can be maintained for an adequate function.
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Humanos , Articulações dos Dedos , MovimentoRESUMO
Clinical and experimental observations have demonstrated a relationship between epilepsy and sleep. During slow wave sleep (SWS), facilitation of the epileptic activity has been observed, as well as an inhibition of this activity during the rapid eye movement (REM) stage. On the other hand, during epileptic seizures, sleep inhibition is manifest, but when epileptic activity is present without seizures, an increase in cortical synchronization is encountered. Vagus nerve electrical stimulation (VNS) induces synchronization or desynchronization of cortical activity depending on the stimulation parameters. We have described an inhibition of generalized convulsive activity induced either by electrical (kindling) or chemical (penicillin) stimulation of the temporal lobe amygdala. It has also been demonstrated that VNS induces ponto-geniculo-occipital activity thus suggesting that VNS exerts an influence on epilepsy and sleep. The aim of this study was to analyze the effect of chronic electrical stimulation of the vagus nerve on epilepsy-induced changes in the temporal organization of sleep and wakefulness stages. Ten male cats were stereotaxically implanted to record conventional sleep. In addition, a bipolar stainless steel electrode bound to a cannula was directed to the central nucleus of the temporal lobe amygdala. Finally, a bipolar hook stainless steel electrode was fixed on the left vagus nerve at the level of the larynx. One microliter of saline solution containing 100 IU of sodium penicillin G (Pn) was injected into the amygdala to induce an epileptic state. The left vagus nerve was stimulated with 30-s impulses in an hour, five times a day; subsequently brain electrical activity was recorded for 8 hours. The Pn injection elicited interictal spikes and changes in the temporal organization of sleep and wakefulness stages. The temporal organization of these stages exhibited the following variations: a) increase in the number of phases during wakefulness, b) increment in the number of phases during SWS-I and a diminution in the mean duration of this phase, c) SWS-II total time was increased as well as its percentage, d) latency of REM sleep increased, whereas the number of phases and the total time of this phase decreased. VNS in presence of Pn produced the following changes: a) increase in the latency of the appearance of spikes in 88%, and b) reduction of spike frequency in 40%. With regard to the temporal organization of sleep and wakefulness stages, we observed: a) decrease in the number and total time of SWS-I and SWS-II phases and b) diminution in the latency of onset of the first REM sleep. VNS reverted REM sleep inhibition induced by epilepsy, as well as caused increase in wakefulness and decrease in cortical synchronization and interictal epileptic activity. These effects suggest inactivation of areas that induce REM sleep and also of areas that induce the generalization of epileptic activity localized in brain stem, which send their projections to the anterior brain. With respect to the decrease in both cortical synchronization and somnolence, this might be due to the inhibition, via the solitary tract and locus coeruleus nuclei, of thalamic areas (reticular nucleus), which generate the cortical synchronization. The increase in wakefulness may be due to VNS activation of the basalis nucleus (this pathway originates in the brain stem), which is a system that regulates awake and attention behaviors by its projections, which traverse the thalamic nuclei and connect to the cerebral cortex.
Por las observaciones clínicas y experimentales se sabe que hay una relación entre la epilepsia y el sueño. Se describe durante el sueño de ondas lentas (SOL) una facilitación de la actividad epiléptica y una inhibición durante el sueño de movimientos oculares rápidos (MOR). A su vez, durante las crisis epilépticas se observa una inhibición del sueño y cuando no hay crisis, y sólo se registra actividad epiléptica, se observa un aumento en la sincronización cortical. La estimulación eléctrica del nervio vago (ENV) induce sincronización y desincronización de la actividad cortical según los parámetros de estimulación. Hemos descrito una inhibición de la actividad convulsiva generalizada inducida por la estimulación eléctrica (kindling) y química (penicilina) en la amígdala del lóbulo temporal. También se ha demostrado que la ENV induce la actividad ponto-genículo-occipital (PGO), por lo que se deduce que la ENV tiene influencia tanto en la epilepsia como en el sueño. El objetivo de este trabajo fue analizar el efecto de la estimulación eléctrica crónica del nervio vago sobre los cambios que induce la epilepsia en la organización temporal del sueño y la vigilia. Se implantaron estereotaxicamente a 10 gatos machos para registro convencional de sueño y se introdujo una cánula unida a un electrodo bipolar dirigida hacia el núcleo central de la amígdala del lóbulo temporal. Se colocó además un electrodo en forma de horquilla en el nervio vago izquierdo a nivel de la laringe. Se aplicaron en un microlitro de solución salina, 100 unidades internacionales (UI) de penicilina G sódica (Pn) en la amígdala del lóbulo temporal para inducir la epilepsia. Se estimuló eléctricamente el nervio vago (ENV) izquierdo durante 30 segundos cada hora. En total se aplicaron cinco estimulaciones al día y se registró la actividad eléctrica cerebral durante ocho horas. La Pn produjo espigas interictales y cambios en la organización temporal de las fases del sueño y la vigilia. En la organización temporal de las fases del sueño y la vigilia con la Pn se observó: a) la vigilia aumentó el número de fases, b) el SOL-I aumentó el número de fases y disminuyó la duración promedio de la fase, c) el SOL-II aumentó el tiempo total de la fase así como su porcentaje, d) el sueño MOR aumentó la latencia y disminuyó el número de fases así como el tiempo total de la fase. Con la ENV en presencia de la Pn se observó: a) un aumento en la latencia de aparición de espigas en un 88% y b) una reducción en la frecuencia de las mismas en un 40%. En la organización temporal de las fases del sueño y la vigilia se observó: a) una disminución del número y del tiempo total de las fases del SOL I- II y b) una disminución en la latencia de aparición del primer sueño MOR. La ENV revirtió la inhibición del sueño MOR inducida por la epilepsia, aumentó la vigilia, disminuyó la sincronización cortical y la actividad epiléptica interictal. Estos efectos nos sugieren la inactivación de las áreas que inducen la inhibición del sueño MOR y de las áreas que inducen la generalización de la actividad epiléptica, localizadas en el tallo cerebral y que envían proyecciones hacia el cerebro anterior. Con respecto a la disminución de la sincronización cortical, la reducción de la somnolencia se debería probablemente a la inhibición vía el núcleo del tracto solitario (NTS)-locus coeruleus hacia las áreas del tálamo (núcleo reticular) que generan la sincronización cortical. El aumento de la vigilia se debería a que la ENV activa al núcleo basalis (vía que se origina en el tallo cerebral), que es un sistema que regula la conducta de vigilia y atención por medio de sus proyecciones a través de los núcleos del tálamo y que se conectan a la corteza cerebral.
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Abstract: Introduction. Epileptic activity modifies the endogenous opioid system by increasing its levels at the end of the ictal phase, and in post-ictal and interictal phases. This increase originates a cortical excitatory effect which suppresses both slow wave sleep and REM. The epileptic activity is initiated with the presence of interictal epileptiform activity, which may be induced through penicillin administration into amygdaline nuclei. Interictal epileptiform activity is a widely employed tool used to determine the localization of epileptic foci characterized by the sudden presence of spikes or acute waves in an electroencephalogram (EEG). In the present work, this tool was used to study the participation of the opioid system in the installation and propagation of epileptic activity induced in temporal lobe amygdala. In the epiloptogenetic study, amygdaline interictal epileptiform activity was used to assess changes induced by opioids and an antagonist in the occurrence of interictal activity using an event histogram. Propagation was studied with the cortical topographic mapping technique, which shows EEG frequency components in a power spectrum, as well as the rhythmic EEG patterns. The aim of the present study was to analyze the effect of enkephalins on epileptiform activity induced with penicillin in tem poral lobe amygdala and its propagation to the cerebral cortex. Method. Fifteen male Wistar rats were submitted to an acute preparation; they were anesthetized with urethane (1.2 g/kg, i.p.). A stainless steel bipolar electrode provided with a cannula was directed toward the left amygdaline basolateral nucleus and a second concentric bipolar electrode to the right amygdaline basolateral nucleus. Two types of cortical recordings were carried out: global mapping and restricted areas. The first consisted of the placement of a 16 stainless steel electrode matrix (in which the electrodes from the vertex were removed) on the scalp, taking care that the tips of the electrodes were in contact with the cortex; this arrangement covered the whole cerebral cortex. The second involved a 4x4mm square matrix consisting of 16 equidistant electrodes placed on the cerebral cortex. The cortical recording was a result of placing this matrix in four different positions so that the whole cerebral cortex was monitored. To monitor cortical recordings, experimental groups were injected penicillin into the amygdaline nuclei. To perform global mapping, enkephalins, [D-ala]-methionine and [D-ala]-leucine, were topically applied into the amygdaline nuclei and naloxone was administered systemically. Analogical signals were recorded in a video-tape and were digitized in parallel with an HP workstation. Off-line analysis was carried as follows: a) information recorded in video-tapes was acquired in a computer designed for this purpose, using amygdaline interictal epileptiform activity to plot event histograms; b) EEG digitized signal, obtained from global mapping, was used to obtain a spectral analysis, consisting of color images maps in time and frequency domains, using RBEAM software. The recording of electrical activity obtained with the square matrix was visually analyzed only. At the end of each experiment, animals were perfused and each brain was fixed intracardially with 10% formaldehyde. To verify the recording and sub-cortical injection sites, the rapid procedure was used. Results. During control stages, cortical records showed slow activity in the form of spindles in all the recording channels; this was due to urethane. Penicillin administration in amygdaline nuclei induced epileptiform activity with a specific pattern: immediate appearance after penicillin application with a gradual increase in amplitude until stabilization was reached within 5-10 minutes of administration. Analyses of global mapping in the frequency domain showed a specific mode of amygdaline interictal epileptiform activity propagation, starting in ipsilateral temporal, prefrontal and fron tal cortices, appearing subsequently in contralateral prefrontal and frontal cortices, and finally in temporal cortex. In the time domain spectrum, an electric dipole generating an interictal spike was found in cerebral cortex. Restricted areas mapping approach showed interictal epileptiform activity and its propagation along the ipsilateral fronto-temporal region. Data revealed an antero-posterior medial cortical activation spreading with decreasing intensity toward occipital regions. Application of enkephalins-[D-ala]-methionine and [D-ala]-leucine produced no epileptic activity, but an increase in basal EEG of cortical epileptiform activity was detected, as well as a decrease in amplitude and frequency of amygdaline epileptiform activity. Naloxone originated a facilitatory effect, since its administration induced focal and generalized electrocorticographic seizures. Conclusions. Focal penicillin is a reliable model of interictal spikes, paroxysms and generalized seizures. The study in rats showed a propagation of epileptic activity to prefrontal cortices prior to contralateral amygdala. Our results showed that enkephalins produced a double effect. First, they originated an increase in basal EEG in temporal cortical areas, as well as a putative participation in propagation mechanisms. Second, they exerted an inhibitory effect on epilepsy installation mechanisms. The inhibitory effect originated by enkephalins was reverted by naloxone.
RESUMO
Objetivos: Analizar la labor de un grupo de trabajo (GT) multidisiciplinario en la elaboración de un instrumento para valorar el rendimiento de los alumnos durante las sesiones de trabajo de la estrategia de enseñanza conocida como Aprendizaje Basado en Problemas (ABP); así como algunos métodos que sirvieron para la evaluación estadística. Material y Métodos: Se consideró cuatro áreas fundamentales: Las características y organización del grupo de trabajo para desarrollo de instrumentos de evaluación académica debe incluir personas que desean trabajar en equipo y coordinadores expertos en su área; se requiere además de tiempo, desarrollo de habilidades nuevas y revisiones minuciosas para lograr un instrumento práctico y válido; asimismo, la utilidad del trabajo se puede demostrar con la calidad de los reactivos que emergen y el reducido numero de reactivos a ser eliminados
Assuntos
Aprendizagem Baseada em ProblemasRESUMO
In Florida and Cuba the stone crab Menippe mercenaria (Say, 1818) is under strong fishing-pressure; nevertheless in the Mexican Caribbean it is considered as sub-utilized and poorly known resource. Artificial shelters ("condominios cubanos") were used to study relative abundance, age structure, claw length-carapace amplitude relation, and population in three seasons and four sectors at BahÝa Ascension, Quintana Roo, Mexico. The abundance varied according to the sector and sampling season: population was higher in the south and during the north wind ("Nortes") season (January to March). The carapace amplitude was directly proportional to claw length (r2 = 0.83, 0.97 and 0.89; p < 0.05 in females, males and total, respectively). The results suggest that specimens with 37.5 and 67.5 mm of carapace amplitude are the most limited regarding refuge availability in the Bay.
Assuntos
Animais , Feminino , Masculino , Braquiúros , Água do Mar , Biometria , México , Densidade Demográfica , Estações do AnoRESUMO
El método tradicional para analizar el electroencefalograma (EEG) durante el sueño se ha basado en la inspección visual, hoja por hoja, de los registros de varias horas de sueño de los sujetos, hombres o animales experimentales. Muchas de las características eléctricas pueden ser detectadas y analizadas utilizando este método, pero otras no. Esto se debe a que la inspección visual es un método en el dominio del tiempo, en el cual no son evidentes las frecuencias embebidas en el trazo, ni las relaciones de fase entre eventos electrográficos. En el EEG visualizado pueden medirse algunas características relacionadas con el dominio de la frecuencia, pero sólo en una forma elemental, es decir, la frecuencia y forma de una onda en particular. Pero los cambios sutiles en la fase y las desviaciones ligeras en las frecuencias escapan a la vista del observador. Otro obstáculo en la inspección visual del EEG es la cantidad de registro que se puede ver a la vez; usualmente, uno o dos páginas, lo que dificulta mucho la detección de los cambios leves de la frecuencia. Se ha diseñado y probado un método computacional que soluciona algunos de los problemas intrínsecos de la calificación tradicional del EEG, sobre todo en los registros de sueño de toda la noche. Este programa computacional puede generar una imagen que condensa la evolución de hasta 8 horas continuas de EEG, lo que representa una "abstracción" de la evolución del EEG en el dominio de la frecuencia. Para lograr esto, se calcula el espectro de potencia de cada época de 4 segundos durante toda la noche de registro, y se grafica como una imagen trimensional sólida. Además, se puede graficar simultáneamente la potencia en otros canales del registro, como el electrooculograma (EOG) y el electromiograma (EMG), con el fin de lograr una visualización inmediata de las transiciones de las fases del sueño durante el registro. Se obtuvieron datos de la aplicación de este programa en los registros del EEG (8 horas) de seres humanos. El programa computacional que se presenta fue escrito y probado en una ULTRA SPARC Creator I. utilizando compiladores C++ GNU
Assuntos
Humanos , Adulto , Análise de Fourier , Eletroencefalografia , Gráficos por Computador , Polissonografia/instrumentação , Polissonografia/métodos , Sono/fisiologiaRESUMO
Los autores proponen demostrar que inyectando 10 U. de ocitocina sintética reducen el tiempo de alumbramiento y la pérdida sanguínea materna. Asimismo determinan la reducción de la pérdida hemática y la aceleración de alumbramiento, no registrando en 36 pacientes estudiadas ninguna complicación materna