Erythropoietin Attenuates the Apoptosis of Adult Neurons After Brachial Plexus Root Avulsion by Downregulating JNK Phosphorylation and c-Jun Expression and Inhibiting c-PARP Cleavage.

In the present study, the effects of erythropoietin (EPO) on preventing adult neurons from apoptosis (introduced by brachial plexus avulsion) were examined, and the mechanism was analyzed. Fifty injury rat models were established in this study by using micro-hemostat forceps to pull out brachial plexus root from the intervertebral foramen in supine position. These models were divided into EPO group (avulsion + 1000 U/kg subcutaneously on alternate days) and control group (avulsion + normal saline). C5-T1 spinal cord was harvested at days 1, 2, 4, 7, and 14. Compared with the control group, the apoptosis of spinal motoneurons was significantly decreased on days 4 and 7 in the EPO group, which was also approved by TUNEL examination results. The detection of p-JNK and expression of c-Jun and cleavage of cleaved PARP (c-PARP) were also examined by immunohistochemistry and were increased immediately at day 1, and peaked at day 2, day 2, and day 4 in control group, respectively. However, the amounts were decreased and delayed by EPO treatment significantly at the same time points. In conclusion, the apoptosis of adult spinal motorneurons was associated with JNK phosphorylation, c-Jun expression, and caspase activity, and EPO-mediated neuronal protective effect is proved by downregulating the JNK phosphorylation and c-Jun expression and inhibiting of c-PARP cleavage.

Effects of age on minimum effective volume of local anesthetic for ultrasound-guided supraclavicular brachial plexus block.

BACKGROUND: Involutional changes of peripheral nervous system occur with aging. The aim of the study was to determine the minimum effective volume of local anesthetic required to offer an effective ultrasound-guided supraclavicular brachial plexus block in 50% of middle-aged (< 50 years) and elderly (> 65 years) patients. We hypothesized reduced minimum effective volume of local anesthetic in elderly patients. METHODS: Middle-aged (n = 22) and elderly (n = 22) patients undergoing upper limb surgery received an ultrasound-guided supraclavicular brachial plexus block. Structural analysis of the brachial plexus in supraclavicular region was obtained by measuring the cross-sectional area. The prospective, observer-blinded study method is a previously validated step-up/step-down sequence model where the local anesthetic volume for the next patient is determined by the outcome of the previous block. The starting volume was 30 ml (50 : 50 mixture, 0.5%wt/vol levobupivacaine, 2%wt/vol lidocaine). The minimum effective volume of local anesthetic was determined using Dixon and Masey method. RESULTS: The minimum effective local anesthetic volume significantly differed between middle-aged and elderly [23.0 ml, 95% confidence interval (CI) 13.7-32.3 vs. 11.9 ml, 95% CI 9.3-14.6; 95% CI of the difference 1.6-20.6, P = 0.027]. The cross-sectional area of brachial plexus was 0.95 ± 0.15 in middle-aged and 0.51 ± 0.06 cm(2) in elderly patients (P < 0.001). CONCLUSIONS: Within the present study, we report a reduced minimum effective anesthetic volume for ultrasound-guided supraclavicular block in elderly patients. Additionally, smaller cross-sectional surface area of brachial plexus in the supraclavicular region was observed.

Mathematical models of brachial plexus development during the fetal period: clinical aspects.

BACKGROUND: The brachial plexus is an important anatomical structure. It can be damaged in both the perinatal and postnatal periods as a result of injury. The available literature does not provide much discussion of the development of the brachial plexus in human fetuses. OBJECTIVES: The goal of the study was a mathematical analysis of fetal brachial plexus growth and geometry. MATERIAL AND METHODS: The study examined 220 human brachial plexuses, derived from 110 fetuses (including 50 females - 45.45%) aged 14-32 weeks of fetal life, with a crown-rump length (CRL) ranging from 80 to 233 mm. Anthropological methods, preparation, digital image acquisition, the Image J measurement tool, the Scion Image for Windows program and statistical methods were applied. In each fetus, somatic as well as linear parameters were observed: lengths, diameters and distances between the nerves making up the brachial plexus geometry. RESULTS: In the majority of the linear parameters analyzed, no sexual dimorphism or asymmetry were observed. The following asymmetries and sexual dimorphisms appear to be significant from the clinical point of view: asymmetry in the length of the C7 and Th1 nerve left radix, asymmetry in the diameters of the musculocutaneous nerve on the left and the median and ulnar nerves on the right; as well as an increased distance between nerves roots in female fetuses. The weekly growth of individual parts of the plexus varied, as did the correlation ratios among them. The most rapid growth was observed between the 14th and 18th weeks, and the slowest between the 24th and 28th weeks. Four formulae were used in the mathematical growth model: linear regression, logarithmic function, the von Bertalanffy growth model and the Gompertz curve. CONCLUSIONS: The prenatal development of the brachial plexus is not constant. The applied mathematical functions proved useful in describing its growth rate.

The lesser occipital nerve in fetuses / El nervio occipital menor en fetos

The lesser occipital nerve (LON) is an ascending superficial branch of the cervical plexus that has a variable origin either from the ventral ramus of the second cervical nerve or second and third cervical nerves and is purely sensory. Forty fetuses (right side: 40/80; left: 40/80) with gestational ages between 15 to 28 weeks were microdissected to document the anatomy of the LON. Results: a) Incidence and Morphometry: LON present in 100 percent specimens, with average length on the right and left sides of 23.59 +/- 2.32 mm and 23.45 +/- 2.27 mm, respectively; b) Course: In its ascent towards the occipital region, the LON was located on the splenius capitus muscle in 85 percent of specimens and in 15 percent of the specimens, it ascended vertically on the sternocleidomastoid muscle towards the ear, innervating its superior third; c) Branching pattern: LON displayed (i) single: 70 percent; (ii) duplicate: 26 percent and (iii) triplicate: 4 percent patterns; d) Variation in the course of LON was observed in 6 percent of the specimens. Knowledge of the anatomy and variations of the LON may assist in the understanding of cervicogenic headaches and may be of assistance to anesthetists performing regional anesthesia for surgical procedures in the neck.

El nervio occipital menor (NOM) es una rama ascendente superficial del plexo cervical que tiene un origen variable ya sea del ramo ventral del segundo nervio cervical o de los nervios cervicales segundo y tercero, y es solamente sensitivo. Cuarenta fetos (lado derecho: 40/80; izquierdo: 40/80), con edades gestacionales de 15 a 28 semanas fueron microdisecados para documentar la anatomía del NOM. a) Incidencia y morfometría: el NOM estuvo presente en el 100 por ciento de los especímenes, con una longitud media de los lados derecho e izquierdo de 23,59 +/- 2,32 mm y 23,45 +/- 2,27 mm, respectivamente; b) Curso: en su ascenso hacia la región occipital, el NOM se localiza en el músculo esplenio de la cabeza en el 85 por ciento de las muestras y en el 15 por ciento de las muestras, ascendió verticalmente sobre el músculo esternocleidomastoideo hacia el oído, inervando el tercio superior, c) Patrón de ramificación: el NOM se observa (i) individual: 70 por ciento, (ii) duplicado: 26 por ciento y (iii) triplicado: 4 por ciento de los patrones; d) Variación en el curso de NOM se observó en el 6 por ciento de las muestras. El conocimiento de la anatomía y las variaciones del NOM puede ayudar en la comprensión de los dolores de cabeza cervical y puede ser de ayuda a los anestesiólogos a realizar la anestesia regional para procedimientos quirúrgicos en el cuello.

Anatomia do plexo braquial de macaco-barrigudo (Lagothrix lagothricha) / Anatomy of the brachial plexus of the Woolly-Monkey (Lagothrix lagothricha

The woolly-monkey (Lagothrix lagothricha) is an antropoid belonging to the Atelidae Family which includes the largest neotropical primates. A female cadaver woolly-monkey was fixed in a 10 percent formaldehyde solution and dissected using a stereoscopic magnifying glass and photodocumented. The brachial plexus originated from the spinal nerves C5 to C8 and T1, forming the cranial, medium, and caudal stems, from which derived the peripheral nerves; those nerves had similar origin and innervation area when compared to plexuses from other primates, with the exception of the musculocutaneous nerve that crossed the coracobraquial muscle. Data from studies with brachial plexus from primates allow the access to valuable information regarding the morphology of those animals, and could also assist in the establishment of anatomical parameters among species, which could then contribute to anesthetic procedures and injury treatments.

O macaco-barrigudo (Lagothrix lagothricha) é um antropóide pertencente à Família Atelidae que possui os maiores primatas neotropicais. Um cadáver fêmea de macaco-barrigudo foi fixado com solução de formaldeído a 10 por cento, posteriormente dissecado com o auxílio de lupa estereoscópica e fotodocumentado. O plexo braquial originou-se dos nervos espinhais C5 a C8 e T1, formando os troncos cranial, médio e caudal, dos quais derivaram os nervos periféricos que se assemelharam na origem e no território de inervação com os plexos de outros primatas, com exceção do nervo musculocutâneo que atravessou o músculo coracobraquial. Pesquisas sobre o plexo braquial de primatas fornecem dados que disponibilizam o acesso a informações valiosas sobre a morfologia destes animais e auxiliam no estabelecimento de parâmetros anatômicos entre as espécies, contribuindo também no tratamento de injúrias e procedimentos anestésicos.

Análise comparativa da origem do plexo branquial de catetos (Tayassu tajacu) / Comparative analysis of the origin of the brachial plexus of the collared peccary (Tayassu tajacu)

O cateto (Tayassu tajacu) pertence à familia Tayassui-dae e é caracterizado por "colar" de pêlos brancos ao redor do pescoço que se estende bilateralmente cranialmente aos ombros. Pode ser encontrado do sudoeste dos Estados Unidos da América até a Argentina. Na literatura verificou-se a falta de dados a respeito da anatomia funcional do cateto especialmente trabalhos que envolvem a anatomia do plexo braquial. Visando elucidar o comportamento do plexo braquial do cateto e com a finalidade de contribuir para o desenvolvimento da anatomia comparada, realizou-se esta pesquisa. Utilizou-se 30 animais de idades diferentes (13 fêmeas e 17 machos) provenientes do Centro de Multiplicação de Animais Silvestres, Universidade Federal Rural do Semi-árido, Mossoró, Rio Grande do Norte. Após o abate, realizou-se a dissecação bilateral dos plexos braquiais e registraram-se os resultados através de desenhos esquemáticos e as disposições agrupadas em tabelas para subseqüente análise estatística e obtidas as freqüências percentuais. Observou-se que o plexo braquial de catetos é resultado das comunicações estabelecidas, principalmente, entre os ramos ventrais dos três últimos nervos espinhais cervicais (C6, C7 e C8) e dos dois primeiros nervos espinhais torácicos (T1 e T2), tendo uma contribuição do quarto e quinto nervos cervicais em 16,67 por cento e 50,00 por cento dos casos, respectivamente. Em 40,00 por cento das dissecações a formação do plexo, mais freqüente, foi do tipo C6, C7, C8, T1 e T2. Os principais nervos derivados do plexo braquial dos catetos e suas respectivas origens foram: nervo supraescapular (C6 e C7), nervo subscapular (C5, C6 e C7 ou C6 e C7), nervo axilar (C6 e C7), nervo músculocutâneo (C7 e C8), nervo mediano (C7, C8, T1 e T2), nervo ulnar (C8, T1 e T2), nervo radial (C8, T1 e T2), nervos peitorais craniais (C7) e caudais (C7 e C8), nervo toracodorsal (C6, C7 e C8), nervo torácico longo (C7 e C8) e nervo torácico lateral (C8, T1 e T2).

Collared peccary (Tayassu tajacu) belongs to the Tayassuidae family, characterized by a "collar" of white hairs that cross behind the neck and extend bilaterally in front of the shoulders. It can be found from south-western United States to Argentina. In the literature a shortage of data is verified regarding the functional anatomy of the collared peccaries, especially of studies that involve the anatomy of the brachial plexus. To elucidate the behavior of this plexus of collared peccaries and with the purpose to contribute for the development of compared anatomy, this study was accomplished. Thirty animals of different ages were used (17 males and 13 females) coming from the Wild Animal Multiplication Center of the "Universidade Federal Rural do Semiárido" Mossoró, Rio Grande do Norte, Brazil. After slaughter bilateral dissection of the brachial plexuses took place, and the results were registered in schematic drawings and the dispositions grouped in tables for subsequent statistical analysis based on the percentile frequency. It was found that the Plexus brachialis of collared peccaries is the result of established communications, mainly among the Rami ventrales of the last three cervical nerves and of the first two thoracic nerves, having a contribution of the fourth and fifth cervical nerves in 16.67 percent and 50.00 percent of the cases, respectively. In 40.00 percent of the dissections the most frequent plexus was of the type C6, C7, C8, T1 and T2. The main nerves derived from brachial plexus of the collared peccaries and its respective origins had been: Nervus suprascapularis (C6, C7), Nn. subscapulares (C5, C6 e C7 or C6 e C7), N. axillaris (C6, C7), N. musculocutaneus (C7, C8), N. medianus (C7, C8, T1, T2), N. radialis (C8, T1, T2), N. ulnaris (C8, T1, T2), cranialis (C7), and caudalis (C7, C8) Nn. pectorales , N. thoracodorsalis (C6, C7, C8), N. thoracicus longus (C7, C8), and N. thoracicus lateralis (C8, T1, T2).

Análise comparativa da origem do plexo branquial de catetos (Tayassu tajacu) / Comparative analysis of the origin of the brachial plexus of the collared peccary (Tayassu tajacu)

O cateto (Tayassu tajacu) pertence à familia Tayassui-dae e é caracterizado por "colar" de pêlos brancos ao redor do pescoço que se estende bilateralmente cranialmente aos ombros. Pode ser encontrado do sudoeste dos Estados Unidos da América até a Argentina. Na literatura verificou-se a falta de dados a respeito da anatomia funcional do cateto especialmente trabalhos que envolvem a anatomia do plexo braquial. Visando elucidar o comportamento do plexo braquial do cateto e com a finalidade de contribuir para o desenvolvimento da anatomia comparada, realizou-se esta pesquisa. Utilizou-se 30 animais de idades diferentes (13 fêmeas e 17 machos) provenientes do Centro de Multiplicação de Animais Silvestres, Universidade Federal Rural do Semi-árido, Mossoró, Rio Grande do Norte. Após o abate, realizou-se a dissecação bilateral dos plexos braquiais e registraram-se os resultados através de desenhos esquemáticos e as disposições agrupadas em tabelas para subseqüente análise estatística e obtidas as freqüências percentuais. Observou-se que o plexo braquial de catetos é resultado das comunicações estabelecidas, principalmente, entre os ramos ventrais dos três últimos nervos espinhais cervicais (C6, C7 e C8) e dos dois primeiros nervos espinhais torácicos (T1 e T2), tendo uma contribuição do quarto e quinto nervos cervicais em 16,67 por cento e 50,00 por cento dos casos, respectivamente. Em 40,00 por cento das dissecações a formação do plexo, mais freqüente, foi do tipo C6, C7, C8, T1 e T2. Os principais nervos derivados do plexo braquial dos catetos e suas respectivas origens foram: nervo supraescapular (C6 e C7), nervo subscapular (C5, C6 e C7 ou C6 e C7), nervo axilar (C6 e C7), nervo músculocutâneo (C7 e C8), nervo mediano (C7, C8, T1 e T2), nervo ulnar (C8, T1 e T2), nervo radial (C8, T1 e T2), nervos peitorais craniais (C7) e caudais (C7 e C8), nervo toracodorsal (C6, C7 e C8), nervo torácico longo (C7 e C8) e nervo torácico lateral (C8, T1 e T2).

Collared peccary (Tayassu tajacu) belongs to the Tayassuidae family, characterized by a "collar" of white hairs that cross behind the neck and extend bilaterally in front of the shoulders. It can be found from south-western United States to Argentina. In the literature a shortage of data is verified regarding the functional anatomy of the collared peccaries, especially of studies that involve the anatomy of the brachial plexus. To elucidate the behavior of this plexus of collared peccaries and with the purpose to contribute for the development of compared anatomy, this study was accomplished. Thirty animals of different ages were used (17 males and 13 females) coming from the Wild Animal Multiplication Center of the "Universidade Federal Rural do Semiárido" Mossoró, Rio Grande do Norte, Brazil. After slaughter bilateral dissection of the brachial plexuses took place, and the results were registered in schematic drawings and the dispositions grouped in tables for subsequent statistical analysis based on the percentile frequency. It was found that the Plexus brachialis of collared peccaries is the result of established communications, mainly among the Rami ventrales of the last three cervical nerves and of the first two thoracic nerves, having a contribution of the fourth and fifth cervical nerves in 16.67 percent and 50.00 percent of the cases, respectively. In 40.00 percent of the dissections the most frequent plexus was of the type C6, C7, C8, T1 and T2. The main nerves derived from brachial plexus of the collared peccaries and its respective origins had been: Nervus suprascapularis (C6, C7), Nn. subscapulares (C5, C6 e C7 or C6 e C7), N. axillaris (C6, C7), N. musculocutaneus (C7, C8), N. medianus (C7, C8, T1, T2), N. radialis (C8, T1, T2), N. ulnaris (C8, T1, T2), cranialis (C7), and caudalis (C7, C8) Nn. pectorales , N. thoracodorsalis (C6, C7, C8), N. thoracicus longus (C7, C8), and N. thoracicus lateralis (C8, T1, T2).

A parallel comparison of age-related peripheral nerve changes in three different strains of mice.

Strain-specific differences contributing to spontaneous age-related peripheral nerve changes were examined in three different strains of 100-week-old female mice housed under the same conditions over the same period: inbred C57BL and C3H strains, and the hybrid B6C3F1 strain. A lower incidence of obesity and significantly lower body weight, grasping power of fore- and hind-limbs, blood lipid level, tail-flick latency and motor nerve conduction velocity were observed in C57BL mice; significantly lower body temperature, blood glucose and HbA1c levels were observed in C3H mice. Histological examination conducted on isolated sciatic nerves and brachial plexuses revealed peripheral nerve lesions, characterized by axonal degeneration and remyelination, in all strains. Although the extent of histopathologic change in nerve fibers was similar in quality to those observed in all three mouse strains, the incidence and severity of nerve lesions in B6C3F1 and C3H mice were significantly greater than those observed in C57BL mice.

Synaptogenesis in the brachial and lumbosacral enlargements of the spinal cord in the postnatal opossum, Monodelphis domestica.

Synaptic proteins were localized in light microscopy on sections of the brachial and lumbosacral enlargements of the spinal cord of postnatal opossums, Monodelphis domestica, to determine whether their expression correlates with the development of major motor pathways and simple motor behaviors. The tissues were fixed, cryoprotected, frozen, cut in 15-micrometer sections, and processed immunohistochemically using antibodies against synaptophysin, synaptotagmin-I, or SNAP-25. Immunolabeling was observed in the presumptive white matter before the presumptive gray matter, suggesting that the proteins are evidenced in growing axons before the onset of synaptogenesis, and it was observed in presumed propriospinal axons before most presumed descending axons of supraspinal origin. In the newborn opossum, the immunolabeling was scant in the gray matter and was limited to the periphery of the ventral horn, and indeed few synapses were seen in electron microscopy in nonexperimental material. Labeling increased in intensity and spread throughout the gray matter until 5-7 weeks, when it was no longer found in the white matter and resembled the adult pattern of labeling. Considering the location and relative intensity of the immunolabeling for the three proteins over time in the two enlargements, synaptogenesis occurs according to three general gradients: rostrocaudal, ventrodorsal, and lateromedial. These gradients match those of spinal cord and limb development, and of the growth of descending axons into the cord. Synaptogenesis is most intense when the spinal sensorimotor reflexes begin to be expressed.

Chick wing innervation. I. Time course of innervation and early differentiation of the peripheral nerve pattern.

Anterograde transport of horseradish peroxidase was used to map the initial projection patterns of motor and sensory axons innervating the wing of the chick embryo. Injections which resulted in labeling large numbers of motor and sensory axons, separately or in combination, were used to define the time course of innervation and to visualize the progressive morphogenesis of the peripheral nerve pattern. Motor axons emerged from the spinal cord and accumulated near the ventromedial border of the myotome where they remained for up to 16 hours before growing into the plexus region and limb bud. Despite the known later time of sensory neuron production, the first sensory axons projected to the wing at the same time as motor axons. When axons first entered the wing bud, they were distributed in two loosely organized sheets of axon fascicles, one projecting to dorsal muscle mass, the other to ventral muscle mass. The width of the sheets was between one-third to one-half the width of the wing bud, and this distance was more than twice the diameter of the proximal nerve trunks measured at stage 28. In the proximal limb the basic pattern of peripheral nerves emerged gradually from stages 26 to 28. During these stages, the loosely organized sheets of axonal fascicles seen at younger stages were progressively transformed into several coherent nerve trunks and muscle nerves extended from common nerve trunks. The implication of these observations is that many outgrowing axons appear not to follow preformed pathways corresponding to the mature peripheral nerve branching pattern. This pattern may instead result from axonal recognition of cues within a largely undifferentiated limb bud, and from the subsequent bundling together of loosely organized axon fascicles. These events occur concurrently with limb growth and differentiation.

[Fascicular structure of the middle trunk of the brachial plexus in human post-fetal life]. / Budowa peczkowa pnia srodkowego splotu ramiennego w zyciu pozaplodowym czlowieka.

Thickness of the middle trunk of the brachial plexus, size of cross-section area of its fascicles, number of fascicles and size of index of the fascicle's area has been examined bilaterally on bodies of 34 males and 34 females who died at the age between the 11th and 86th year of life. The middle trunk was present in all the cases and it always made continuation of the root of the brachial plexus coming from C7. The internal structure of the middle trunk is characterized by a great individual variability and asymmetry. The examined features of the middle trunk underwent big changes in postnatal life, mostly up to 22nd year of life. The thickness of the trunk increased 3.5 times, the size of the cross-section area of fascicles--3.2 times, and the number of fascicles by 59%, but the index of fascicle's area decreased by over 11%. The participation of fascicles of different thickness in the structure of the trunk also changed.

[Terminal divisions of the inferior trunk of the brachial plexus in man]. / Koncowe czesci pnia dolnego splotu ramiennego u czlowieka.

The thickness of terminal divisions of the inferior trunk, size of cross-section area of fascicles, number of fascicles and index of the fascicle's area have been examined bilaterally on the bodies of 69 men. The anterior division compared with the posterior division was 4.9 times thicker, the size of its cross-section area of fascicles was 4.1 times greater than in the posterior one. The index of fascicle's area was smaller by 16.3% in the anterior than in posterior division. The fascicles with the cross-section area up to 0.500 sq mm occurred more often in the anterior than in posterior division, and the fascicles with the cross-section area greater than 0.5 sq mm occurred more often in the posterior one than in the anterior division. The studied features of the terminal parts of the inferior trunk, apart from the number of fascicles, underwent big changes during postnatal life, especially up to the 22nd year of life.