Caracterización de la Lámpara Flash-LED: EBNeuro Usada para Adquirir Potenciales Evocados Visuales en Ratas / Characterization of the Flash-LED Lamp: EBNeuro Used to Acquired Visual Evoked Potentials in Rats

Resumen: La señal de la amplitud en análisis de Potenciales Evocados Visuales (PEVs) es una variable que depende del tipo y posición de los electrodos, de la fuente, del estímulo y por consecuente, de la intensidad luminosa por lo que es fundamental reportarla para cada diseño experimental y así, garantizar su reproducibilidad. El objetivo de este trabajo es caracterizar una lámpara con 96 LEDs para la adquisición de PEVs en ratas. Se midió la iluminancia y la intensidad luminosa promedio en un sistema espacial XYZ de 8 cm3 aplicable a un sistema estereotáxico para la fijación de ratas. Se realizaron desplazamientos cada 2 cm en cada plano. Se observó que debido a la distribución geométrica de los LEDs la distribución de la iluminancia no sigue la ley del inverso cuadrado, ya que aumenta conforme la lámpara se aleja. Finalmente, se seleccionó una coordenada para la colocación del ojo de la rata empleando una intensidad luminosa promedio para la adquisición del PEV de 1.043 cd e iluminancia de 128.77 luxes a una distancia ojo-lámpara de 9 cm. Una vez caracterizada la intensidad luminosa y de acuerdo con los PEVs obtenidos, esta lámpara puede utilizarse para estudios PEV en ratas en investigaciones posteriores.

Abstract: Signal amplitude for recordings of Visual Evoked Potentials (VEPs) is a variable dependent on the type and position of the electrodes, the source, the stimulus and consequently the luminous intensity; therefore, it is relevant to report it to assure experimental reproducibility. The objective of this work is to characterize flash lamp with 96 LEDs in order to perform the acquisition of VEPs in rats. We measure the illuminance and mean light intensity on space system XYZ of 8 cm3 corresponding to a stereotaxic frame for rodents. Displacements were performed every 2 cm in each plane. Because of the geometric distribution of the LEDs in the EBNeuro lamp the spatial distribution of illuminance does not follow the law of the inverse square, because the illuminance increases as the lamp goes away. Finally a spatial coordinate was selected for the rat eye positioning were the mean luminous intensity was 1.043 cd and 128.77 luxes of illuminance at an eye-lamp distance of 9 cm. According to the obtained VEPs and spatial characterization this lamp can be used for acquire of recordings PEV in rats for further investigations.

Agressive pediatric myofibromatosis in a two-year-old child.

INTRODUCTION: Aggressive paediatric myofibromatosis is an autosomal recessive disease characterized by fibroblastic proliferation from cells originated in muscle-aponeurotic tissue. Its etiology is unknown, and the average age of the reported cases is 7 years old. The tumor exhibits rapid painless growth and appears attached to muscle tissue and/or bone. The treatment of choice is conservative surgical excision despite of early relapses has been reported. OBSERVATION: A 2-year-old patient, with no morbid history, presented with a large swelling in the left submandibular region, firm, neither defined limits nor inflammatory characteristics. Its size doubled 2 months after an incisional biopsy. CT images showed great compromise of the left mandibular body with expanded and thinned cortical bone. The MRI showed extension towards the pharynx. Histopathological findings were elongated fibroblastic and ovoid cells arranged in bundles and fascicles within fibromyxoid stroma, an image consistent with the diagnosis. The treatment consisted in a conservative exeresis of the tumor, preserving the jaw. Control 1 year after surgical removal shows no signs of relapse and the mandibular structure has been restored. DISCUSSION: The large size of the lesion and bone involvement at such an early age evidenced a very aggressive lesion, however, supported by a previous biopsy, we performed a conservative treatment, which only caused the loss of a dental germ, impossible to take off from the intraosseous tumor. The control of this type of lesions requires a longer follow-up.

[A safe technique of Le Fort I osteotomy in bilateral cleft patients]. / Une technique sûre d'ostéotomie de Le Fort I chez les patients porteurs d'une fente labio-alvéolo-palatine bilatérale.

Le Fort I osteotomy is often needed in bilateral cleft patients. The usual approach to the maxillae may compromise the premaxillary vascularisation. We present a subperiosteal exposure preserving two paramedian vascular pedicles that respect premaxillary blood-supply.

Low condylectomy as the sole treatment for active condylar hyperplasia: facial, occlusal and skeletal changes. An observational study.

The purpose of this study was to measure the changes in facial, occlusal, and skeletal relationships in patients with active unilateral condylar hyperplasia whose sole treatment was a low condylectomy. A retrospective observational descriptive study was conducted. All patients had undergone a low condylectomy as the sole or initial surgical treatment. The size of the condylar segment removed was decided by matching the affected side with the healthy side, leaving them both like the healthy one. The length of the ramus was measured using panoramic X-ray (distance from the highest part of the condyle to the mandibular angle). Facial, occlusal, and skeletal changes were evaluated using clinical, photographic, and radiological records before and after surgery. Condylectomy as the sole treatment for patients with active condylar hyperplasia allowed improvements to the alterations produced by this pathology, such as chin deviation, tilted lip commissure plane, tilted occlusal plane, angle of facial convexity, unevenness of the mandibular angles, and length of the mandibular ramus. The occlusal relationship also improved with orthodontic and elastic therapy. To conclude, low condylectomy as a sole and aetiological treatment for patients with active condylar hyperplasia allowed improvements to alterations produced by this pathology.

[Cross-sectional study of deviated nasal septum in unilaterally operated fissures]. / Estudio transversal de la desviación del tabique nasal en las fisuras unilaterales operadas.

INTRODUCTION: Nasal septum deviation is one the most significant nasal deformities among cleft and lip patients and its anatomical variations along the anterior-posterior axis within the nasal cavity has not been specified. AIM: To define whether there are differences in the degree of nasal septum deviation between the anterior, middle and posterior areas of the nasal cavity in operated unilateral cleft lip and palate patients. MATERIAL AND METHOD: Twenty-nine unilateral complete cleft lip and palate patients, between 5 and 17 years, attending San Borja Arriarán Hospital and the University of Chile's School of Dentistry were included. The nasal septum deviation index was measured at different depths across the anteroposterior axis by cone-beam computed tomography. A random effects model was performed for data analysis. RESULTS: The nasal septum deviation index presented differences between the three planes studied. The plane with lesser deviation was the anterior, while the plane with greater deviation was the posterior. These differences resulted statistically significant (P < 0.05). CONCLUSION: In complete unilateral cleft and lip patients mainly the posterior part of the nasal septum should be corrected, because there is a greater deviation in that area.

Estudio transversal de la desviación del tabique nasal en las fi suras unilaterales operadas / Fertility survey of patients opened on of cryptorchidism in the pediatric age

Introducción. La desviación del tabique nasal es una de las deformaciones nasales más significativas entre los pacientes fisurados unilaterales y sus variaciones anatómicas dentro de la cavidad nasal no han sido del todo precisadas en relación al eje antero-posterior Objetivo. Determinar si existen diferencias en el grado de desviación del tabique nasal entre las zonas anterior, media y posterior de la cavidad nasal, en pacientes operados de fi sura-labio-máxilo-palatina unilateral. Material y método. Veintinueve pacientes operados de fi sura labiomáxilo-palatina unilateral entre 5 y 17 años, controlados en el Hospital San Borja Arriarán y Facultad de Odontología de la Universidad de Chile fueron incluidos. El coeficiente de desviación del tabique nasal fue medido a distintas profundidades a lo largo del eje antero-posterior mediante tomografía computarizada de haz cónico, y comparado utilizando un programa para estimar modelos de efectos aleatorios. Resultados. El coeficiente de desviación del tabique nasal presentó diferencias entre los tres planos estudiados. El plano con menor desviación fue el anterior, mientras que el plano con la mayor desviación fue el posterior. Estas diferencias resultaron estadísticamente significativas (P<0,05).Conclusiones. Durante la corrección quirúrgica del tabique nasal de los pacientes portadores de fi sura unilateral completa se debe prestar mayor atención a la porción posterior de esta estructura, ya que se encuentra más comprometida por la deformidad (AU)

Introduction. Nasal septum deviation is one the most significant nasal deformities among cleft and lip patients and its anatomical variations along the anterior-posterior axis within the nasal cavity has not been specified.Aim. To defi ne whether there are differences in the degree of nasal septum deviation between the anterior, middle and posterior areas of the nasal cavity in operated unilateral cleft lip and palate patients. Material and method. Twenty-nine unilateral complete cleft lip and palate patients, between 5 and 17 years, attending San Borja Arriarán Hospital and the University of Chile’s School of Dentistry were included. The nasal septum deviation index was measured at different depths across the anteroposterior axis by cone-beam computed tomography. A random effects model was performed for data analysis. Results. The nasal septum deviation index presented differences between the three planes studied. The plane with lesser deviation was the anterior, while the plane with greater deviation was the posterior. These differences resulted statistically significant (P<0.05).Conclusion. In complete unilateral cleft and lip patients mainly the posterior part of the nasal septum should be corrected, because there is a greater deviation in that area (AU)

[Use of an external fixator in open tibial shaft fractures as definitive treatment]. / Uso de fijador externo en fracturas diafisarias de tibia expuestas como tratamiento definitivo.

BACKGROUND: We conducted a study evaluating the clinical and radiologic results of the open tibial shaft fractures using an external fixator as definitive treatment. METHODS: Clinical, observational, descriptive, prospective and longitudinal study. Forty-six patients were included, 40 males (87%) and 6 females (13%), whose age was 31.02 +/- 14.62 years; the time elapsed from the accident to admission in the Emergency Room was 1-16 hours, with a mean of 5.1 +/- 3.35 hours. Ten patients (21.74%) had a Gustilo grade I open fracture, and 36 patients (78.26%) a Gustilo grade II fracture. They were also classified according to the AO classification, with the following resulting groups: 13 (28.9%) patients were A3, 12 (26.1%) were B3, 8 (17.4%) B1, 8 (17.4%) were B2, and 5 (10.9%) were A2. The dynamization of the fixator was done at a mean of 11.56 +/- 1.10 weeks. RESULTS: Forty-three patients had healing at 23.51 +/- 3.62 weeks; Gustilo I fractures healed at 22.8 +/- 3.5 weeks; Gustilo II fractures at 23.7 +/- 3.7 weeks, with a P value of 0.48. In 3 patients (6.53%), due to absence of healing, the external fixator was exchanged for an intramedullary nail with a bone graft, with healing occurring at 18 weeks. Six infections (13%) were reported at the nail insertion site; angulations ranged from 0 degrees to 8 degrees, which is tolerable. CONCLUSIONS: This fixator is safe in properly selected patients, since the few complications that occurred are similar to other reports using different internal fixation methods.

Ischemic heart disease associated with vincristine and doxorubicin chemotherapy.

OBJECTIVE: To report the ocurrence of ischemic heart disease (IHD) in a patient with multiple myeloma treated with vincristine and doxorubicin. CASE SUMMARY: A 46-year-old man developed a Q-wave inferior and right-ventricle myocardial infarction with postinfarction angina after receiving his third cycle of vincristine and doxorubicin for immunoglobulin A multiple myeloma. Angiography showed two small filling defects consistent with thrombi in the distal right coronary artery. DISCUSSION: IHD may be a serious but uncommon complication of treatment with several chemotherapeutic agents. It is likely that chemotherapy played a role in the development of IHD in our patient. Several putative mechanisms for vascular toxicity have been associated with chemotherapy. CONCLUSIONS: Chemotherapy with vincristine and doxorubicin may play a role in the ocurrence of IHD. Physicians should possess an awareness of this potentially serious complication of chemotherapy.

Bilayer reconstitution of voltage-dependent ion channels using a microfabricated silicon chip.

Painted bilayers containing reconstituted ion channels serve as a well defined model system for electrophysiological investigations of channel structure and function. Horizontally oriented bilayers with easy solution access to both sides were obtained by painting a phospholipid:decane mixture across a cylindrical pore etched into a 200-microm thick silicon wafer. Silanization of the SiO(2) layer produced a hydrophobic surface that promoted the adhesion of the lipid mixture. Standard lithographic techniques and anisotropic deep-reactive ion etching were used to create pores with diameters from 50 to 200 microm. The cylindrical structure of the pore in the partition and the surface treatment resulted in stable bilayers. These were used to reconstitute Maxi K channels in the 100- and 200-microm diameter pores. The electrophysiological characteristics of bilayers suspended in microchips were comparable with that of other bilayer preparations. The horizontal orientation and good voltage clamping properties make the microchip bilayer method an excellent system to study the electrical properties of reconstituted membrane proteins simultaneously with optical probes.

[Electrocardiographic abnormalities in subarachnoid hemorrhage]. / Alteraciones electrocardiográficas en la hemorragia subaracnoidea.

INTRODUCTION: It has been described a great variety of electrocardiographic abnormalities in the acute phase of the subarachnoid hemorrhage (SAH), which are more frequent in patients with severe neurologic impairment and when there is myocardial damage. The presence of electrocardiographic tracings compatible with acute myocardial infarction (AMI) in the acute phase of the SAH is rare. CLINICAL CASE: We present a 77-year-old patient with an extensive SAH and an electrocardiographic pattern suggesting anterior transmural AMI, with a fatal outcome in a few hours. CONCLUSIONS: It should pay more attention to the possibility of cardiac complications in the SAH. Myocardial ischemia and SAH may coexist. The presence of electrocardiographic abnormalities in the acute phase of the SAH is not always indicative of cardiac pathology.

Alteraciones electrocardiográficas en la hemorragia subaracnoidea / Electrocardiographic abnormalities in subarachnoid hemorrhage

Introducción. Se han descrito una gran variedad de alteraciones electrocardiográficas en la fase aguda de la hemorragia subaracnoidea (HSA), que son más frecuentes en pacientes con alteración neurológica grave y cuando existe lesión miocárdica. La presencia de trazados electrocardiográficos compatibles con un infarto agudo de miocardio en la fase aguda de la HSA es rara. Caso clínico. Presentamos una paciente de 77 años con una HSA extensa y alteraciones electrocardiográficas compatibles con un infarto agudo de miocardio anterior transmural, con desenlace fatal en pocas horas. Conclusiones. Debería prestarse más atención a la posibilidad de complicaciones cardíacas en la fase aguda de la HSA. La isquemia miocárdica y la HSA pueden coexistir. La presencia de alteraciones electrocardiográficas en la fase aguda de la HSA no siempre es indicativa de patología cardíaca (AU)

[The clinical practice guidelines of the Sociedad Española de Cardiología on cardiomyopathies and myocarditis]. / Guías de práctica clínica de la Sociedad Española de Cardiología en miocardiopatías y miocarditis.

Myocardial diseases are a extraordinarily heterogeneous group of processes that only have in common the fact that they involve heart muscle and that they cause a wide spectrum of myocardial dysfunction. The approach of the management and treatment of the cardiomyopathies is a continuous matter of discussion because the vast majority of alternatives in this field have not been based on the best scientific possible evidence and, since except for the case of heart failure associated with dilated cardiomyopathy. The majority of different options have not been studied by means of large (or even small) randomized trials. Nevertheless, this chapter has tried to provide the reader with different approaches on how to deal with important clinical problems in dilated, hypertrophic and restrictive cardiomyopathies, and in myocarditis as well. For this, we have utilized the most relevant information found coupled with our best clinical judgment, although we admit that many of the clinical recommendations can be controversial.

Características cefalométricas en el síndrome de Beckwith-Wiedemann / Cephalometric features of Beckwith-Wiedemann's syndrome

Doce niños afectados por el síndrome de Beckwith-Wiedemann fueron estudiados cefalométricamente por medio del análisis arquitectural y estructural cráneo-facial de Delaire, en la búsqueda de características comunes. Los resultados muestran una normalidad de las estructuras craneanas, en la cara, la posición adelantada del maxilar y la biprotrusión dentoalveolar son características casi constantes, la falta de desarrollo vertical del maxilar superior y la mordida abierta anterior están presentes en una gran mayoría de los pacientes estudiados. En nuestra opinión, estas características son deformidades secundarias al excesivo tamaño de la lengua más que una condición primaria de la malformación (AU)

Hemopericardio con taponamiento debido a perforación cardíaca por marcapasos transitorio / Hemopericardium with tamponade due to heart perforation caused by transient pacemaker

El hemopericardio resulta habitualmente de traumatismos, neoplasias pericárdicas o metastásicas, disección aórtica, rotura o perforación cardíaca, coagulopatías, tratamiento anticoagulante, uremia o tuberculosis. La acumulación de líquido en el pericardio en cantidad suficiente para causar una obstrución severa del flujo de salida de los ventrículos da lugar al taponamiento cardíaco (TC). El pulso paradójico consiste en una disminución mayor de la normal (10 mmHg) de la tensión arterial sistólica con la inspiración. El pulso paradójico es característico pero no patognomónico del TC. El valor predictivo positivo y negativo del pulso paradójico en el diagnóstico del TC se ha estimado en el 81 por ciento y 40 por ciento, respectivamente. Presentamos un paciente con pulso paradójico con un hemopericardio con TC debido a una perforación cardíaca causada por un marcapasos transitorio implantado 48 horas antes. La perforación cardíaca siguiendo a la implantación endovenosa de un marcapasos cardíaco es una complicación excepcional y el TC es extremadamente raro (AU)

[Central lipoma of the mandible. A new case]. / Lipome central de la mandibule. Une nouvelle observation.

Lipomas are benign neoplasms affecting many organs of the body with adipose tissue. As a bone central lesion they represent less than 1% of all lipomas. In the literature lipomas are reported in different bones: calcaneum, ribs, fibula, phalanges, ulna, frontal and parietal bone. In the jaws 8 cases have been reported, most of them representing radiographic findings the clinician diagnosing cyst or tumor, specially odontogenic tumor. No preference has been reported for any gender, age or race but the condition appears after the fourth decade. We report a case of central lipoma in the mandible with the clinical, radiological and histopathological findings and discuss its origin.

Inhibition of human immunodeficiency virus type 1 long terminal repeat-driven transcription by an in vivo metabolite of oltipraz: implications for antiretroviral therapy.

Metabolite III (MIII, 7-methyl-6,8-bis(methylthio)pyrrolo[1,2-alpha]pyrazine), a major in vivo metabolite of oltipraz (OLT, 5-pyrazinyl-4-methyl-1,2-dithiole-3-thione), appears to disrupt human immunodeficiency virus type 1 (HIV-1) replication at a point distal to integration of the viral genome into host DNA. We report that MIII (but not OLT) is a nontoxic inhibitor of long terminal repeat (LTR)-driven expression of beta-galactosidase in phorbol-12-myristate-13-acetate (PMA)-stimulated and unstimulated 293.27.2 cells (ED50 = 14 +/- 1 and 41 +/- 4 microM, respectively). Electrophoretic mobility-shift assays (EMSA) reveal that MIII does not significantly reduce the PMA-induced DNA binding activities of NF-kappa B or AP-1. Although the mechanism by which MIII inhibits LTR-driven transcription remains unclear, the antiviral synergism of OLT and MIII in vitro are likely due their independent activities. Whether this translates into antiviral synergy in vivo is being examined by comparing OLT and MIII pharmacokinetics to the pharmacodynamic effects of orally-administered OLT in patients with p24 antigenemia.

[Anatomic bone and dento-alveolar changes in patients with lip incompetence]. / Modifications anatomiques squelettiques et dento-alvéolaries chez les sujets atteints d'incompétence labiale.

Twenty young patients with clinical labial incompetence have been studied cefalometrically using Delaire's Analysis, in order to determine anatomical alterations who explains this condition. In all of them we have found some anatomical alteration in sagital or vertical plane or both, in maxillary or mandibular squeletal bases or their dento-alveolar squeletic unit. Knowledge of anatomical factors contributing or determining labial incompetence is the key of the planification and execution of an etiologic approach, what is the best way to obtain physiological rapport and consequently good aesthetic results.