Revisão de anatomia e correlações clínicas do tronco encefálico, parte i: bulbo / Review of brain anatomy and clinical correlations, part i: medulla

O Tronco encefálico (TE) é uma estrutura singular do sistema nervoso central, pois nele passam tratos sensoriais ascendentes da medula espinal, tratos sensoriais da cabeça e do pescoço, os tratos descendentes motores originados no prosencéfalo (divisão mais rostral do encéfalo), e as vias ligadas aos centros de movimento dos olhos. Contém ainda os núcleos dos nervos cranianos e está envolvido na regulação do nível de consciência através de projeções ao prosencéfalo oriundas da formação reticular. Todas essas estruturas coexistem em um espaço muito exíguo, o que faz com que o TE seja um local muito sensível às alterações patológicas, sendo que os pacientes apresentam muitos sinais neurológicos mesmo com lesões muito pequenas nesse local. Compreender a anatomia interna do TE é essencial para o diagnóstico neurológico e a prática da medicina clínica. Outros profissionais da saúde também se beneficiam desse conhecimento para melhor manejo dos seus pacientes neurológicos. Essa revisão apresenta detalhes da anatomia macroscópica e microscópica do bulbo, bem como seus correlatos clínicos frente às lesões mais comuns dessa divisão particular do TE, conhecidas como síndromes bulbares.

The brainstem is a unique structure in the central nervous system, since it gives way to ascending sensory tracts from the spinal cord, sensory tracts from the head and neck, motor descending tracts originating from the forebrain, and the pathways connected to the eye movement centers. It also contains the cranial nerve nuclei and is involved in the regulation of consciousness levels through projections to the forebrain originating in the reticular formation. All these structures coexist in a very small space, which makes the brainstem very sensitive to pathological changes, with patients presenting several neurological symptoms even with very small brainstem lesions. Understanding the internal anatomy of the brainstem is essential for neurological diagnosis and the practice of clinical medicine. Other health professionals also benefit from this knowledge to better manage their neurological patients. This review presents detailed information on the macroscopic and microscopic anatomy of the medulla, as well as its clinical correlates in the face of the most common lesions of this particular division of the brainstem, known as medullary syndromes.

Expression of AIF, PARP, and miRNAs MIR-145, MIR-210, and MIR-486 associated with apoptosis in the corpus cavernosum of rats subjected to chronic alcoholism model / Expresión de AIF, PARP y miRNAs MIR-145, MIR-210 y MIR-486 asociados con apoptosis en el cuerpo cavernoso de ratas sometidas a modelo de alcoholismo crónico

SUMMARY: Previous studies from our group described the consequences of using ethanol on penile erection. Nevertheless, the molecular mechanisms surrounding microRNAs, apoptosis process and their relationship with erectile dysfunction associated with alcohol consumption are still poorly understood. The objective of this analysis was to evaluate the mechanism of apoptosis by the expression of AIF and PARP, as well as their regulatory microRNAs: miR-145, miR-210 and miR-486, in the corpus cavernosum of rats submitted to a semivoluntary alcoholism model. For this study 24 Wistar rats were divided into two groups: control (C) and treated with 20 % ethanol (A) for seven weeks. The corpus cavernosum samples were prepared for immunohistochemical analysis of AIF and PARP protein expression, and microRNAs miR-145, miR-210, miR-486 gene expression in cavernous tissue was performed by real time PCR. The immunohistochemical analysis showed little nuclear positive labeling for the protein PARP and AIF in the corpus cavernosum of control and ethanol treated animals. After analysis of miR-145, -210 and -486 microRNA expression in the 12 animals studied, no results were found with significant statistical difference between the control and alcoholized groups. The expression of AIF and PARP and their regulatory microRNAs involved in apoptotic process (miR-145, miR-210 and miR-486) were not altered in the corpus cavernosum of rats submitted to semivoluntary alcoholism.

RESUMEN: Estudios previos de nuestro grupo describieron las consecuencias del uso de etanol en la erección del pene. Sin embargo, los mecanismos moleculares que rodean a los microARN, el proceso de apoptosis y su relación con la disfunción eréctil asociada con el consumo de alcohol aún no se conocen bien. El objetivo de este análisis fue evaluar el mecanismo de apoptosis mediante la expresión de AIF y PARP, así como sus microARN reguladores: miR-145, miR-210 y miR-486, en el cuerpo cavernoso de ratas sometidas a un modelo de alcoholismo semivoluntario. Se dividieron 24 ratas Wistar en dos grupos: control (C) grupo de ratas tratadas con etanol al 20 % (A) durante siete semanas. Las muestras del cuerpo cavernoso se prepararon para el análisis inmunohistoquímico de la expresión de la proteína AIF y PARP, y la expresión del gen microRNAs miR-145, miR-210, miR-486 en tejido cavernoso se realizó por PCR en tiempo real. El análisis inmunohistoquímico mostró escaso etiquetado nuclear positivo para la proteína PARP y AIF en el cuerpo cavernoso de los animales de control y tratados con etanol. Después del análisis de la expresión de microARN miR-145, -210 y -486 no se encontraron resultados con diferencias estadísticas significativas entre los grupos control y alcoholizados. La expresión de AIF y PARP y sus microARN reguladores involucrados en el proceso apoptótico (miR-145, miR-210 y miR-486) no se alteraron en el cuerpo cavernoso de las ratas sometidas a alcoholismo semivoluntario.

Aspects of the macro and microscopic anatomy of the sciatic nerve in Wistar rats / Aspectos de la anatomía macro y microscópica del nervio ciático en ratas Wistar

The present study seeks to systematize morphological and morphometrical parameters and brings new data on the main branch of the lumbosacral plexus ­ i.e., sciatic nerve ­ in Wistar rats aged four and seven weeks. Sixteen female were divided into two groups, namely animals aged four weeks, and animals aged seven weeks. The specimens were studied at proximal and distal segments of the right hind limb sciatic nerves. Semi-thin transverse sections (0.25 µm thickness) were stained with 1 % toluidine blue, and the morphometric analysis was processed through the KS 400 software. Except for the number of fascicles and fascicular diameter, no differences were found between the proximal and distal segments. We observed differences when morphometric values were compared between 4- and 7- week old animals, with some exceptions (number of fascicles and myelinated fibers, and capillary area and number). The macroscopic data disagree with a previous description of the sciatic nerve being composed by two fascicles. Instead, sciatic nerve's only fascicle trifurcates or quadrifurcates at the distal third of the thigh. The total capillary area and density were calculated, and these are the first referential data for the sciatic nerve. Histograms of myelinated fiber and axons considering the animal ages were built. The results presented here are important because experimental studies, mainly studies on nerve regenerations require comparison with normal reliable data.

El objetivo fue sistematizar los parámetros morfológicos y morfométricos y traer nuevos datos sobre el ramo principal del plexo lumbosacro - es decir nervio ciático - en ratas Wistar de 4 a 7 semanas. Dieciséis ratas fueron divididas en dos grupos, con 4 y 7 semanas de edad. Las muestras estudiadas fueron los segmentos proximal y distal del nervio ciático derecho. Secciones delgadas (espesor 0,25 mm) fueron teñidas con azul de toluidina al 1 % y el análisis morfométrico se llevó a cabo utilizando el programa KS 400. Excepto para el número de fascículos y diámetro fascicular, no se encontraron diferencias entre los segmentos proximal y distal. Fueron observadas diferencias cuando se compararon los valores morfométricos entre animales de 4 y 7 semanas, con algunas excepciones (número de fascículos y fibras mielinizadas, área y número de capilares). Los datos macroscópicos no están de acuerdo con la descripción anterior del nervio ciático siendo compuesto por dos fascículos. En cambio, sólo trifurcación o cuadrifurcación fueron encontrados en el tercio distal del muslo. El área total capilar y la densidad fueron calculadas y estos constituyen los primeros datos de referencia para el nervio ciático. Se construyeron histogramas de fibras mielínicas y axones, teniendo en cuenta las edades de los animales. Los resultados presentados aquí son importantes porque los estudios experimentales, en especial aquellos sobre la regeneración nerviosa, requieren comparación con datos confiables normales.

Hind limb sensory innervation in rats: comparison between sural and saphenous nerve morphometry / Inervación sensorial de los miembros posteriores en ratas: comparación morfométrica entre los nervios sural y safeno

Although numerous studies investigate sensory recovery of the hind paw of the rat after nerve damage, still no comprehensive overview of its normal innervation is present in the literature. We investigated the morphometry of myelinated fibers in the sural and saphenous nerves and analyzed their size distributions in young rats. Six 30-day-old female Wistar rats were perfused with 2.5% glutaraldehyde and their right and left sural and saphenous nerves were prepared for light microscopy and morphometry. Morphometric data were compared between segments (proximal versus distal) and sides (right versus left) for the same nerves. Also, segments from right or left sides were compared between nerves (sural versus saphenous). Both, the sural and saphenous nerves, exhibited proximal to distal symmetry on both sides as well as left-right symmetry. Histograms of the diameter of the myelinated fibers were unimodal in both nerves, regardless of segments or sides with the peaks of the fibers size occurring between 2.5 and 4.0 µm. The axon distributions reflected the myelinated fiber distributions, with the sural and saphenous nerves peaking between 1.5 and 2.0 µm. The G ratio (the ratio between the axon and fiber diameters) distributions were also unimodal, with peaks at 0.6 for both nerves. This study contributes to the literature with information on the myelinated fibers morphometry from the two sensory nerves responsible for the rat hind limb innervation. This information is valuable for a better understanding of the possible contribution of collateral sprouting from the sural or saphenous nerves on the paw sensory territory recovery observed after one of these nerves is damaged.

Aunque numerosos estudios investigan la recuperación sensorial del miembro pélvico o posterior de la rata después del daño en los nervios, aún no existe en la literatura una visión global de su inervación normal. Investigamos la morfometría de fibras mielínicas de los nervios sural y safeno y analizamos sus distribuciones de tamaño en ratas jóvenes. Seis ratas Wistar de 30 días de edad fueron perfundidas con 2,5% de glutaraldehído, se prepararon los nervios sural y safeno derecho e izquierdo para microscopía de luz y morfometría. Datos morfométricos fueron comparados entre los segmentos (proximal vs distal) y laterales (derecho vs izquierdo) para los mismos nervios. Además, los segmentos de los lados derecho e izquierdo se compararon entre los nervios (sural vs safeno). Ambos nervios sural y safeno exhibieron una simetría proximal a distal en ambos lados, así como una simetría izquierda-derecha. Histogramas del diámetro de las fibras mielinizadas eran unimodales en ambos nervios, independientemente de los segmentos o de los lados, siendo los peaks del tamaño de las fibras entre 2,5 y 4,0 micras. Las distribuciones de los axones reflejan las distribuciones de fibras mielinizadas, de los nervios sural y safeno que alcanzaban entre 1,5 and 2,0 µm. La relación de G (relación entre los diámetros de los axones y de fibra) eran también unimodales, alcanzando 0,6 para ambos nervios. Este estudio contribuye a la literatura con los datos de la morfometría de fibras mielinizadas de ambos nervios sensoriales responsables de la inervación de la extremidad pélvica de la rata. Esta información es valiosa para una mejor comprensión de los nervios sural y safeno en la recuperación sensorial del miembro después de que uno de estos nervios ha sido dañado.

Ineficácia da laserterapia aplicada no trajeto do nervo e nas raízes medulares correspondentes / Lack of effectiveness of laser therapy applied to the nerve course and the correspondent medullary roots

Objetivo: Verificar a influência da irradiação do laser de baixa intensidade na regeneração do nervo fibular comum de ratos após lesão por esmagamento. Métodos: Foram utilizados 25 ratos, divididos em três grupos: 1) nervo intacto, e não tratados; 2) nervo lesado, e não tratado; 3) nervo lesado, e laser irradiado sobre a região medular correspondente às raízes do nervo ciático e subsequentemente no trajeto do nervo lesado. A irradiação foi realizada por 14 dias consecutivos. Resultados: Foram avaliados por meio da análise funcional da marcha, através do índice funcional do peroneiro, e por análise morfométrica através do número total de fibras nervosas mielinizadas e sua densidade, número total de células de Schwann, número total de vasos sanguíneos e sua área, diâmetro mínimo da fibra e razão-G. Conclusão: De acordo com a análise estatística, não houve diferença significativa entre os grupos, e os autores concluem que a irradiação do laser de baixa intensidade possui pouca ou nenhuma influência na regeneração nervosa e recuperação funcional. Trabalho experimental.

Objective: To investigate the influence of low intensity laser irradiation on the regeneration of the fibular nerve of rats after crush injury. Methods: twenty-five rats were used, divided into three groups: 1) intact nerve, no treatment; 2) crushed nerve, no treatment; 3) crush injury, laser irradiation applied on the medullary region corresponding to the roots of the sciatic nerve and subsequently on the course of the damaged nerve. Laser irradiation was carried out for 14 consecutive days. Results: animals were evaluated by functional gait analysis with the peroneal functional index and by histomorphometric analysis using the total number of myelinated nerve fibers and their density, total number of schwann cells, total number of blood vessels and the occupied area, minimum diameter of the fiber diameter and G-quotient. Conclusion: according to the statistical analysis there was no significant difference among groups and the authors conclude that low intensity laser irradiation has little or no influence on nerve regeneration and functional recovery. Laboratory investigation.

Can Wistar rats be used as the normotensive controls for nerve morphometry investigations in spontaneously hypertensive rats (SHR)? / Ratos Wistar podem ser utilizados como os controles normotensos dos ratos espontaneamente hipertensos (SHR) em investigações morfométricas de nervos periféricos?

PURPOSE: We compared the sural nerve morphology among Wistar (WR), Wistar-Kyoto (WKY) and Spontaneously hypertensive (SHR) rats, including the nerve fascicles and myelinated fibers morphometry. METHODS: Age matched (20 weeks) female WR (N=6), WKY (N=6) and SHR (N=7) had their right and left sural nerves removed, embedded in epoxy resin, and observed by light microscopy. Morphometric analysis was performed with the aid of computer software. RESULTS: Despite presenting the same age, WR were heavier than WKY and SHR, as were SHR compared to WKY. Systolic arterial pressure was higher in SHR compared to WR, but no differences between SHR and WKY or WR and WKY were observed. The sural nerves were morphometrically symmetric between proximal and distal segments on the same side and between sides in all strains with no differences in the myelinated fiber number. Schwann cell number and density were smaller in SHR and G ratio was larger in SHR, indicating that SHR have thinner myelinated fibers. CONCLUSION: Sural nerve morphology is similar between WKY and WR, allowing the use of WR as the SHR controls in morphological investigations involving peripheral neuropathies.

OBJETIVO: Comparar a morfologia do nervo sural em ratos Wistar (WR), Wistar Kyoto (WKY) e espontanemanete hipertensos (SHR), incluindo a morfometria dos fascículos e fibras mielínicas. MÉTODOS: Os nervos surais direito e esquerdo de WR (N=6), WKY (N=6) e SHR (N=7), com 20 semanas de idade foram removidos e preparados para inclusão em resina epóxi e microscopia de luz. A morfometria foi realizada com o auxílio de um programa de computador. RESULTADOS: Apesar de apresentarem a mesma idade, WR são mais pesados que os WKY e SHR. Ainda, SHR são mais pesados que os WKY. A pressão arterial sistólica foi significativamente maior nos SHR comparados aos WR, sem diferença entre WKY e SHR ou WR e WKY. Os nervos surais são morfometricamente simétricos entre segmentos proximal e distal e entre lados direto e esquerdo nas três diferentes linhagens, sem diferença no número de fibras mielínicas. O número e a densidade de células de Schwann foram menores e a razão G foi maior nos SHR, indicando a presença de fibras mielínicas com bainha mais fina. CONCLUSÃO: A morfologia do nervo sural é semelhante ente WR e WKY, permitindo o uso de WR como controles dos SHR nas investigações envolvendo neuropatias periféricas.

Transmission electron microscopy studies of the vestibulocochlear nerve in chronic diabetic rats / Estudios de microscopía electrónica de transmisión del nervio vestibulococlear en ratas diabéticas crónicas

It is widely described in the literature that diabetic patients present hearing impairment. Despite the histological alterations of the internal ear structures in these patients as well as in experimental models of diabetes, to the best of our knowledge, an histological evaluation of the vestibulocochlear nerve have not been performed. In the present study, ultrastructural alterations are described and compared between a spinal nerves and a cranial nerve in rats with chronic induced diabetes. Male Wistar rats (n = 12), fed with standard diet from the animal care facility at 42 days of age were used. Induced diabetic animals (n=6) were fasted for 12 hours prior to being injected intraperitoneally with streptozotocin (STZ - 60mg/kg) in a single dose. Control animals (n=6) received (0.01 mol/l citrate buffer, pH 4.5) vehicle alone. Ten weeks after STZ injection the animals were perfused intracardially with Karnovsky solution. Right and left vestibulocochlear nerves were dissected and histologically processed for epoxy resin embedding. Samples were imaged with the transmission electron microscope. Large myelinated fibers with morphological signs of axonal atrophy in the vestibulocochlear nerves were readily observed. These results suggest that chronic STZ-induced diabetes in rats caused alterations in the myelinated fibers and Schwann cells, compatible to the classic diabetes signs and symptoms. Morphological alterations of the vestibulocochlear nerve in diabetes is described for the first time and contributes information for a better understanding of why there are changes in hearing observed in diabetic patients.

Se ha descrito ampliamente en la literatura que los pacientes diabéticos presentan discapacidad auditiva. En estos pacientes, a pesar de las alteraciones histológicas de las estructuras del oído interno, así como en modelos experimentales de diabetes, que mejoran nuestro conocimiento, la evaluación histológica del nervio vestibulococlear no ha sido realizada. Se describen y comparan las alteraciones ultraestructurales entre un nervio espinal y uno craneal en ratas con diabetes crónica inducida. Fueron utilizadas 12 ratas Wistar machos, de 42 días de edad, alimentadas con dieta estándar. Los animales diabéticos inducidos (n = 6) se mantuvieron en ayuno por 12 horas antes de ser inyectados por vía intraperitoneal con estreptozotocina (STZ - 60mg/kg) en una sola dosis. Los animales control (n = 6) sólo recibieron inyección de 0.01 mol/l buffer, citrato pH 4,5. Diez semanas después de la inyección de STZ, los animales fueron perfundidos intracardiacamente con solución de Karnovsky. Los nervios vestibulococlear derecho e izquierdo fueron disecados y procesados histológicamente para ser incluidos en resina epoxy. Las muestras fueron estudiadas con microscopio electrónico de transmisión. Fueron observadas fácilmente, grandes fibras mielinizadas con signos morfológicos de atrofia axonal en los nervios vestibulococlear. Estos resultados sugieren que la diabetes crónica inducida por STZ en ratas causó alteraciones en las fibras mielínicas y células del neurilema, compatible, con los signos y síntomas clásicos de la diabetes. Alteraciones morfológicas del nervio vestibulococlear en la diabetes son descritas por primera vez, lo que aporta información para una mejor comprensión de por qué hay cambios en la audición en los pacientes diabéticos.

Diabetic peripheral neuropathies: a morphometric overview / Neuropatías diabéticas periféricas: una visión general morfométrica

Diabetes is now considered one of the main threats to human health in the 21st century and many researchers are dedicated to investigate the physiopathology of the disease, with further insights on the managements of its major complications. Since understanding the pathophysiology of the major complications of diabetes and their underlying processes is mandatory, experimental models of the disease may be useful as they allow the recognition of the early mechanisms involved in the long-term complications of diabetes. Peripheral nerve involvement is highly frequent in diabetes mellitus and it has been documented that one third of diabetic patients have peripheral neuropathy. The true prevalence is not known and reports vary from 10 percent to 90 percent in diabetic patients, depending on the criteria and methods used to define neuropathy. In this review, the most common experimental models of diabetes are presented and the pathological findings on major peripheral nerves are discussed. Also, the insights brought by morphometry to the diabetic neuropathy research are highlighted.

La diabetes es considerada hoy una de las principales amenazas para la salud humana en el siglo 21 y muchos investigadores se dedican a investigar la fisiopatología de la enfermedad, con otras visiones sobre el manejo de sus principales complicaciones. Dado que la comprensión de la fisiopatología de las principales complicaciones de la diabetes y sus procesos subyacentes es obligatorio, modelos experimentales de la enfermedad pueden ser útiles ya que permiten el reconocimiento de los primeros mecanismos implicados en las complicaciones a largo plazo de la diabetes. El compromiso de los nervios periféricos es muy frecuente en la diabetes mellitus y se ha documentado que un tercio de los pacientes diabéticos tiene neuropatía periférica. La prevalencia es desconocida y los informes varían de 10 por ciento a 90 por ciento en los pacientes diabéticos, en función de los criterios y métodos utilizados para definir la neuropatía. En esta revisión, se presentan los modelos experimentales más comunes de diabetes y se discuten los hallazgos patológicos en los principales nervios periféricos. Además, se destacan las visiones presentadas por la morfometría de la investigación la neuropatía diabética.

Efeitos da aplicação do laser de baixa potência na regeneração do nervo isquiático de ratos / Effects of low-power laser on injured rat sciatic nerve regeneration

Os nervos periféricos sofrem constantes lesões de origem traumática, o que resulta em perdas funcionais. A terapia com laser de baixa potência vem sendo utilizada para minimizar os efeitos maléficos da inflamação e acelerar o processo de cicatrização dos tecidos lesados. Este estudo teve como objetivo verificar o efeito da irradiação do laser 830 nm no comportamento do nervo isquiático de ratos submetido a esmagamento. Foram utilizados 20 ratos, todos tendo tido o nervo isquiático esmagado, divididos em 4 grupos (n=5): P7 e P14, tratamento placebo por 7 e 14 dias; L7 e L14, tratamento por laser (dosagem de 4 J/cm²) por 7 e 14 dias. Os animais dos grupos P7 e P14 foram submetidos aos mesmos procedimentos, mas com o laser desligado. Os parâmetros analisados foram presença de infiltrado inflamatório e fibroblastos, destruição da bainha de mielina e degeneração axonal. Na análise estatística foi observada diferença estatística com relação a três parâmetros: os animais do grupo L14 apresentaram maior quantidade de fibroblastos (p=0,0001), menor degeneração da bainha de mielina (p=0,007) e menor quantidade de infiltrado inflamatório (p=0,001). A aplicação do laser de baixa potência contribuiu para a redução do processo inflamatório decorrente da lesão do nervo isquiático de ratos...

Peripheral nerves are commonly subject to traumatic injuries, leading to functional loss. Low-power laser therapy has been used in order to minimize harmful effects of inflammation and to accelerate healing of injured tissues. The purpose of this study was to assess the effect of 830 nm-laser irradiation on rat sciatic nerves submitted to crush. Twenty male Wistar rats had their sciatic nerve crushed and were divided into 4 groups (n=5): Sham7 and Sham14, placebo-treated for 7 and 14 days; L7 and L14, laser-treated (at 4 J/cm²) for 7 and 14 days. Sham group animals were submitted to the same procedures, but with the laser turned off. Assessed parameters were inflammatory infiltrates, fibroblasts, myelin sheath destruction, and axonal degeneration. The statistical analysis showed significant differences in three parameters: L14 animals showed more fibroblasts (p=0.0001), lesser myelin sheath degeneration (p=0.007), and lesser inflammatory infiltrates (p=0.001). Low-power laser therapy hence contributed to reduce the inflammatory process due to rat sciatic nerve injury...

Atresia of the coronary sinus ostium to the right atrium with a persistent left superior vena cava / Atresia del ostium del seno coronario en el atrio derecho con una vena cava superior izquierda persistente

The coronary sinus has lately assumed an important role in the cardiologic clinic once it has been widely used in invasive procedures of the heart. Commonly, it is used during the electrodes implants for the epimiocardic monitoring of the cardiac rhythm, through a biventricular pace maker. These invasive procedures are not possible in hearts with an atresic coronary sinus ostium. In the presence of this anomaly, another may occur: the development of the "Marchal" vein which is a remaining of the left superior vena cava (LSVC). This happens so that the venous blood from the heart can drain into the right atrium, by a communication between the LSVC and the left brachiocephalic vein. The presence of a LSVC brings difficulties when performing an invasive procedure in order to access the right atrium through the superior vena cava, usually done in the cardiologic clinic. Moreover, the LSVC crossing over the left atrium is vulnerable to cardiovascular surgical interventions, confirmed by clinical reports. In the present study, 400 formalin fixed hearts from male cadavers, aged between 35 and 80 years, were investigated, particularly for the anatomy of the coronary sinus. The obliterated ostium of the coronary sinus to the right atrium associated with a persistent LSVC was present in only one (0.25 percent). We performed a diameter study of these structures since they were dilated due to the venous blood from the heart draining into the right atrium, by a communication between the LSVC and the left brachiocephalic vein. We also perform a literature review of these cases and discuss our finding in relation to its clinical importance.

El seno coronario recientemente ha asumido un papel importante en la clínica cardiológico, siendo ampliamente utilizado en procedimientos invasivos del corazón. Comúnmente, se utiliza en los implantes de los electrodos para el monitoreo epimiocárdico del ritmo cardiaco, a través de un ritmo biventricular establecido. Estos procedimientos invasivos no son posibles en los corazones con una atresia del ostium del seno coronario. En presencia de esta condición, se puede producir otra anomalía: el desarrollo de la vena de "Marchal" la cual es un vestigio de la vena cava superior izquierda (VCSI). Esto provoca que la sangre venosa del corazón pueda drenar en el atrio derecho, por una comunicación entre la VCSI y la vena braquicefálica izquierda. La presencia de una VCSI trae dificultades a la hora de realizar un procedimiento invasivo con el fin de acceder al atrio derecho a través de la vena cava superior, usualmente hecho en la clínica cardiológica. Por otra parte, el cruzamiento de la VCSI sobre el atrio izquierdo es vulnerable en las intervenciones quirúrgicas cardiovasculares, confirmado por informes clínicos. En el presente estudio, 400 corazones fijados en formalina provenientes a cadáveres de sexo masculino, con edades comprendidas entre los 35 y 80 años, fueron investigados, en particular por la anatomía del seno coronario. El ostium obliterado del seno coronario al atrio derecho asociado con una VCSI persistente estuvo presente en sólo una muestra (0,25 por ciento). Se realizó un estudio del diámetro de estas estructuras dilatadas debido a que la sangre venosa drena desde el corazón hacia el atrio derecho, por una comunicación entre la VCSI y la vena braquicefálica izquierda. También se realiza una revisión de la literatura de estos casos y se discuten nuestros hallazgos en relación con su importancia clínica.

Arterial diameter of the celiac trunk and its branches: anatomical study / Diâmetro arterial do tronco celíaco e seus ramos: estudo anatômico

PURPOSE: Despite the fact that anatomical variations of the celiac trunk are well explored in the literature, information on these vessels diameters is scanty. The aims of the present study were to describe the arterial diameters of the celiac trunk and its main branches, and to investigate if these diameters are altered in those cases presenting anatomical variations of these vessels. METHODS: Twenty-one formalin fixed adult male cadavers were appropriately dissected for the celiac trunk identification and arterial diameter measurements. Arteries measured included the celiac trunk and its main branches (splenic artery, left gastric artery and common hepatic artery), as the proper hepatic artery, right gastric artery, the left and right hepatic arteries and the gastroduodenal artery. RESULTS: From the 21 cadavers, 6 presented anatomical variations of, at least, one of the above mentioned branches. The average arterial diameter comparisons between groups (normal and variable) clearly showed smaller diameters for variable vessels, but with no significant difference. CONCLUSION: Our data indicates the possibility of a diameter reduction of the celiac trunk main branches in the presence of anatomical variations. This should be taken into account on the selection for the liver transplantation donors.

OBJETIVO: Embora as variações arteriais do tronco celíaco e seus ramos estejam bem documentadas na literatura, o mesmo não ocorre com as descrições dos diâmetros dessas artérias. O presente estudo tem por objetivo descrever os diâmetros arteriais do tronco celíaco e seus ramos em indivíduos normais, bem como investigar se esses diâmetros se apresentam alterados em indivíduos com variação anatômica desses vasos. MÉTODOS: Utilizamos 21 cadáveres adultos, do sexo masculino, previamente fixados em formol a 10 por cento que foram dissecados apropriadamente para a exposição do tronco celíaco e seus ramos. Com o auxílio de um paquímetro digital, foram obtidos os diâmetros externos dos seguintes vasos: tronco celíaco, artéria hepática comum, artéria gástrica direita, artéria esplênica, artéria gástrica esquerda, artéria gastroduodenal, artéria hepática própria e artérias hepáticas direita e esquerda. RESULTADOS: Dos 21 cadáveres avaliados, 6 apresentaram variação anatômica de pelo menos um dos ramos acima mencionados. Ao compararmos os diâmetros arteriais dos vasos normais com os que apresentaram variação, os variáveis apresentaram diâmetros menores, sem, entretanto alcançar níveis de significância. CONCLUSÃO: Nossos dados apontam para a possibilidade de uma diferença de diâmetros entre artérias abdominais normais e variáveis, sendo esse dado de implicância clínica para os transplantes hepáticos de doadores vivos.

Bovine peritoneum protection role on intestinal adhesions to a vascular graft: a morphological analysis / Rol de protección del peritoneo bovino en la adhesión intestinal a un injerto vascular: un análisis morfológico

The present study aimed to experimentally evaluate the protection role of glycerin preserved bovine peritoneum (BP) against intestinal adhesions to a vascular graft. Experiments were performed on 24 adult rabbits, randomly dived into two groups. All animals were submitted to a vascular graft over the infra-renal aorta and vena cava. Group 1(12 animals ) was submitted to a BP patch on the retroperitoneal opening, between the vascular prosthetic graft and the intestinal loops. Group II (12 animals ) had the retroperitoneal opening sutured. After 7, 14, 28 and 60 days, 3 animals of each group were randomly killed and the retro peritoneum, with or without the BPpatch, was removed for histological analysis. The histological analysis showed that the BP stimulated a moderate to intense inflammatory reaction at the beginning of the experiments and on the 60-day evaluation, the inflammatory reaction was mild, limited to the BP border with its histological structure preserved. In conclusion, the BP is a safe and cheap interposition material to be used between vascular grafts and intestinal loops, presenting a protection role against adhesions between them.

El objetivo de este estudio fue evaluar experimentalmente el rol protector del peritoneo bovino (PB) preservado en la glicerina en contra de las adherencias intestinales de un injerto vascular. Los experimentos se realizaron en 24 conejos adultos, randomizados aleatoriamente en dos grupos. Todos los animales fueron sometidos a un injerto vascular sobre la aorta infra-renal y la vena cava. Grupo I (12 animales), fue sometido a un parche PB en una apertura retroperitoneal suturada, entre el injerto vascular y el intestino. Grupo II (12 animales) con la apertura retroperitoneal suturada. Después de 7, 14, 28 y 60 días, 3 animales de cada grupo fueron sacrificados al azar y el retro peritoneo, con o sin el parche de PB, se retiró para el análisis histológico. El análisis histológico mostró que la PB estimuló una moderada a intensa reacción inflamatoria al inicio de los experimentos y en la evaluación de 60 días, la reacción inflamatoria fue leve, limitada a los bordes de la PB con su estructura histológica preservada. En conclusión, la PB es una forma segura y barata de material de interposición para ser utilizada entre injertos vasculares e intestinales, presentando un rol de protección contra adherencias entre ellos.

Long term evaluation of functional and morphological bladder alterations on alloxan-induced diabetes and aging: experimental study in rats / Avaliação funcional e morfológica tardia de alterações na bexiga secundárias ao diabetes induzido por aloxano e no envelhecimento: estudo experimental em ratos

PURPOSE: to evaluate structural and functional effects of Alloxan- induced diabetes and aging on bladder of rats. METHODS: evaluations were performed in three groups: A - 8 weeks of age, B - 44 weeks of age, C - 44 weeks of age with alloxan-induced diabetes. Muscle layer thickness, extracellular matrix fibrosis and collagen were quantified on digital images of bladder samples. Cystometric evaluations before surgical vesical denervation (SVD), included maximum cystometric capacity (MCC), maximum bladder pressure (MBP), bladder contraction frequency (VCF), duration of bladder contraction (DC), threshold pressure (TP) and bladder compliance (BC). After SVD, maximum cystometric capacity (MCC), BC and maximum urethral closing pressure (MUCP) were also measured. RESULTS: Reduced extracellular matrix fibrosis concentration and contraction strength were found in the bladders of group C. Before SVD, bladder compliance was not different between groups. Alterations were observed in MCC after SVD. CONCLUSIONS: We did not notice smooth muscle hypertrophy in Alloxan-induced diabetic rats after 44 weeks. There was alteration in the total and relative amount of fibrosis and collagen. The cystometric studies support the idea that this morphological alterations are important to determine the different bladder functional patterns found in the aging and the Alloxan-induced diabetic animals.

OBJETIVOS: avaliar alterações estruturais e funcionais da bexiga de ratos machos, associadas ao diabetes induzido por aloxano e ao envelhecimento. MÉTODOS: três grupos de animais: A - 8 semanas de idade; B- 44 semanas de idade; C - 44 semanas de idade com diabetes induzido por aloxano, foram avaliados. Realizadas medidas de espessura da camada muscular, fibrose de matriz extracelular e quantidade de colágeno, através de análise de imagem digital dos tecidos. Realizados também testes cistométricos, antes da desnervação vesical cirúrgica (DVC), para avaliar capacidade vesical (CV), intensidade máxima de contração vesical (IMCV) e complacência vesical. Após a DVC, foram avaliadas capacidade vesical após a desnervação (CVAD), complacência vesical (CV) e pressão de perda uretral (PPU). RESULTADOS: não foi observada hipertrofia da camada muscular nas bexigas; houve diminuição da concentração de fibrose da matriz extracelular e diminuição da força contrátil, e aumento da capacidade vesical no grupo C. CONCLUSÕES: a atrofia da camadas muscular da bexiga esta relacionada ao diabetes induzido por aloxano. O envelhecimento, como fenômeno isolado, provoca alterações nos parâmetros funcionais, porém associado ao diabetes, gera alterações na IMCV, CV e CVAD. Existe correlação entre alterações estruturais e funcionais nos animais diabéticos após a desnervação.

Communication Between the Mylohyoid and Lingual Nerves: Clinical Implications / Comunicación entre los Nervios Milohioideo y Lingual: Implicancias Clínicas

The mylohyoid muscle plays an important role in chewing, swallowing, respiration and phonation, being the mylohyoid nerve also closely related to these important functions. It has been postulated that the mylohyoid nerve might have a role in the sensory innervation of the chin and the lower incisor teeth while the role of the mylohyoid nerve in the mandibular posterior tooth sensation is still a controversial issue. Although variations in the course of the mylohyoid nerve in relation to the mandible are frequently found on the dissecting room, they have not been satisfactorily described in the anatomical or surgical literature. It is well known that variations on the branching pattern of the mandibular nerve frequently account for the failure to obtain adequate local anesthesia in routine oral and dental procedures and also for the unexpected injury to branches of the nerves during surgery. Also, anatomical variations might be responsible for unexpected and unexplained symptoms after a certain surgical procedure. We describe the presence of a communicating branch between the mylohyoid and lingual nerves in an adult male cadaver, and discuss its clinical/surgical implications as well as its possible role on the sensory innervation of the tongue. The present study reinforces the idea of a communicating branch between the mylohyoid and lingual nerves, indicating that some of the sensory components of the MHN, instead of innervating the teeth or chin skin, might also innervate the tongue and surgeons might be aware of this variation for the correct interpretation of the unexpected findings after oral nerves injury.

El músculo milohiodeo juega un importante rol en la masticación, alimentación, respiración y fonación, principalmente el nervio milohioideo está íntimamente relacionado en estas importantes funciones. Se ha postulado que el nervio milohioideo pudiese tener un rol en la inervación sensitiva del mentón y de los incisivos inferiores, mientras que el rol del mismo en los dientes posteriores de la mandíbula, es aún una controversia. Aunque variaciones en el curso del nervio milohioideo en relación a la mandíbula son frecuentes de encontrar en la sala de disección, ellas no han sido satisfactoriamente descritas en la literatura anatómica y quirúrgica. Es conocido que variaciones en el patrón de distribución de nervios mandibulares, frecuentemente son consideradas al fracasar en la obtención de una adecuada anestesia en procedimientos orales dentales de rutina y también en la injuria inesperada de los ramos nerviosos durante la cirugía. Además, variaciones anatómicas pueden ser responsables de inesperados e inexplicables síntomas después de ciertos procedimientos quirúrgicos. Describimos la presencia de una ramo comunicante entre los nervios milohioideo y lingual, en un cadáver adulto, de sexo masculino y se discuten sus implicancias clínicas y quirúrgicas y el posible rol en la inervación sensitiva de la lengua. El presente estudio refuerza la idea de un ramo comunicante entre los nervios milohioideo y lingual, indicando algunos de los componentes sensitivos del nervio milohioideo; en cambio, la inervación de los dientes y de la piel del mentón, pudiera inervar la lengua y los cirujanos deberían estar al tanto de esta variación, para una correcta interpretación de los hallazgos inesperados después de una injuria en los nervios.

Common carotid artery bifurcation levels related to clinical relevant anatomical landmarks / Niveles de Bifurcación de la Arteria Carótida Común en Relación a Puntos de Referencia Anatómicos Relevantes en Clínica

En cirugías de cabeza y cuello, las arterias carótidas comunes son importantes puntos de referencia, para defnir el plano de disección, durante cirugías radicales de cuello. Los objetivos del presente estudio fueron agregar información sobre el diámetro de las arterias carótidas y correlacionar el nivel de bifurcación de la arteria carótida común (ACC) con importantes puntos de referencia usados regularmente en la práctica clínica. Para la obtención de los objetivos planteados, fueron evaluados 46 cadáveres formolizados de individuos de sexo masculino. Se obtuvieron los diámetros de las arterias carótidas común, externa (ACE) e interna (ACI), con el auxilio de un caliper digital. No hubo diferencias entre lados derecho e izquierdo, ni tampoco en los niveles estudiados. El nivel de bifurcación de la ACC fue medido en relación a puntos de reparos anatómicos relevantes en clínica (margen superior del cartílago tiroides, ángulo de la mandíbula y lóbulo del pabellón auricular), como también en relación al nivel vertebral. Nuestro estudio mostró que el margen superior del cartílago tiroides fue el punto de referencia más estable para inferir el nivel de bifurcación de la ACC. Es importante mencionar que, de todos los puntos de referencia estudiados, la vértebra cervical fue la única que mostró diferencias entre los lados, siendo más variable el nivel de bifurcación en el lado izquierdo.

In head and neck surgery, the common carotid arteries are important landmarks, defining dissection plane during radical neck surgeries. The objectives of the present study were to add information on the diameter of the carotid arteries and to correlate the common carotid artery (CCA) bifurcation level with important anatomical landmarks used regularly in clinical practice. Forty-six necks from male embalmed human cadavers were evaluated. The CCA as the external (ECA) and internal (ICA) carotid arteries diameters were studied with the aid of an electronic digital caliper. No differences were found between sides in any level studied. The CCA bifurcation level was measured in relation to clinically relevant anatomical landmarks (superior level of the thyroid cartilage, mandible angle and ear lobe) and the bifurcation level according to the cervical vertebra level was also investigated. Our study shows that the superior border of the thyroid cartilage was the most stable anatomical landmark for predicting the CCA bifurcation level. It is important to mention that from all the landmarks studied, the cervical vertebra was the only one to show differences between sides, with the left side bifurcation level more variable than the right side.

Lesão por esmagamento do nervo isquiático de ratos: estudo da vascularização / Rats' ischiatic nerve injury caused by smashing: a vascularization study

Este trabalho teve como objetivo estudar as alterações microvasculares intraneurais aguda em nervo isquiático de rato submetido a esmagamento por diferentes cargas. Foram utilizados 60 ratos machos da linhagem Wistar, distribuídos em grupos experimentais de acordo com a injeção de vasos e com a carga de esmagamento. Os nervos isquiáticos direitos foram isolados e submetidos ao esmagamento com cargas (0,5 Kg, 1 Kg, 5 Kg, 10 kg e 15 kg) por 10 minutos e os nervos isquiáticos esquerdos foram utilizados como controle. Após esmagamento, os animais foram submetidos à cateterização da aorta abdominal e injeção dos vasos, em seguida 30 nervos direitos e esquerdos foram fixados em formol 10 por cento, desidratados e diafanizados para análise longitudinal dos vasos intraneurais e os restantes retirados em toda a sua extensão, cortados em 3 fragmentos, congelados em isopentano em gelo seco e armazenados em freezer -70°C, seccionados transversalmente para análise e contagem dos vasos intraneurais. As análises macroscópica e microscópica mostraram regiões de hematoma endoneural e epineural nas diferentes cargas de esmagamento. A análise morfométrica sugere que a lesão aos vasos intraneurais foi proporcional à carga de esmagamento, causando hematoma endoneural e epineural, que cria microambiente desfavorável para a regeneração das fibras nervosas.

The objective of this paper was to study acute intraneural microvascular changes in a ratÆs ischiatic nerve submitted to smashing with different loads. Sixty male Wistar rats were used and distributed into experimental groups according to vessels injection and smashing load. Right ischiatic nerves were isolated and submitted to smashing with loads (0.5 Kg, 1 Kg, 5 Kg, 10 kg, and 15 kg) for 10 minutes and the left ischiatic nerves served as controls. After smashing, the animals were submitted to catheter implantation on abdominal aorta and vessels injection, then 30 right and left nerves were fixed in 10 percent formol, dehydrated and diaphanized for longitudinal analysis of intraneural vessels and the remaining being fully removed, cut into three fragments, frozen in isopentane with dry ice and stored in a freezer at -70°C, cross-sectioned for analysis and intraneural vessels counting. Gross and microscopic analyses showed regions of endoneural and epineural hematoma on different smashing loads. The morphometrical analysis suggests that intraneural vessels injury was proportional to the smashing load, causing endoneural and epineural hematoma, which creates an unfavorable micro-environment for nervous fibers regeneration.

Avaliação qualitativa e quantitativa das lesões agudas por esmagamento do nervo isquiático do rato / Qualitative and quantitative evaluation of rats' acute injuries caused by ischiatic nerve smashing

Nervos isquiáticos de ratos esmagados com cargas diferentes foram estudados com o auxílio da microscopia de luz. Pesos de 500 g, 1.000 g, 5.000 g, 10.000 g, e 15.000 g foram utilizados por 10 minutos num dispositivo portátil especialmente desenvolvido para este estudo. As análises morfológicas e morfométricas das fibras mielínicas mostraram que a lesão produzida às fibras neurais e ao tecido neural foi diretamente proporcional à carga aplicada e que uma carga de 500 g é suficiente para produzir um dano severo, com lesão importante das estruturas do endoneuro.

Rats' ischiatic nerves smashed with different loads were studied with the aid of light microscopy. Weights of 500 g, 1,000 g, 5,000 g, 10,000 g, and 15,000 g were used for 10 minutes in a portable device, especially developed for this study. Morphological and morphometrical analyses of myelinic fibers showed that the injury produced on neural fibers and on neural tissue was directly proportional to the load applied and that a load of 500 g is enough to produce a severe damage, with an important injury of endoneural structures.

Right retroesophageal subclavian artery

Purpose: The subclavian arteries can vary on their origin, course or length. One of the most common anatomical variations is the right subclavian artery originating as the last branch of the aortic arch. This artery is known as a retroesophageal right subclavian artery or "lusory artery". The right retroesophageal subclavian artery usually is described as not producing symptoms, being most discoveries coincidental. Nevertheless, it may be the site of formation of atherosclerotic plaque, inflammatory lesions or aneurysm. Case Report: The present study describes a case of right retroesophageal subclavian artery and discusses the findings according to their clinical and surgical implications. Conclusion: The anatomic and morphologic variations of the aortic arch and its branches are significant for diagnostic and surgical procedures in the thorax and neck. If a right retroesophageal subclavian artery is diagnosed during aortic arch repair, corrective surgery should be considered. Intensive care patients should be screened before long term placement of nasogastic tube, in order to avoid fistulization and fatal hemorrhage.

Brachial plexus variations in its formation and main branches

Purpose: The brachial plexus has a complex anatomical structure since its origin in the neck throughout its course in the axillary region. lt also has close relationship to important anatomic structures what makes it an easy target of a sort of variations and provides its clinicai and surgical importance. The aims of the present study were to describe the brachial plexus anatomical variations in origin and respective branches, and to correlate these variations with sex, color of the subjects and side of the body. Methods: Twenty-seven adult cadavers separated into sex and color had their brachial plexuses evaluated on the right and left sides. Results: Our results are extensive and describe a large number of variations, including some that have not been reported in the literature. Our results showed that the phrenic nerve had a complete origin from the plexus in 20 percent of the cases. In this way, a lesion of the brachial plexus roots could result in diaphragm palsy. It is not usual that the long thoracic nerve pierces the scalenus medius muscle but it occurred in 63 percent of our cases. Another observation was that the posterior cord was formed by the posterior divisions of the superior and middle trunks in 9 percent. In these cases, the axillary and the radial nerves may not receive fibers from C7 and C8, as usually described. Conclusion: Finally, the plexuses studied did not show that sex, color or side of the body had much if any influence upon the presence of variations.