Pericyte loss and detachment in experimental cisplatin-induced neuropathy / Pérdida y desprendimiento de pericitos en la neuropatía experimental inducida por cisplatino

Cisplatin is an antineoplastic agent with neuropathy as one of its major side effect. However, effective treatment is lacking. Increasing evidence suggests that cisplatin might damage nerve capillaries leading to impaired functions of blood-nerve barrier (BNB) and neuropathy. This study was aimed to examine the effects of cisplatin on pericytes. Rats were either treated with intraperitoneal injection of cisplatin 2 mg/kg twice a week for five continuous weeks. Cisplatin-treated rats showed reduced body weight, thermal hypoalgesia and slow sciatic motor nerve conduction velocity, indicating neuropathy. The density of pericytes in the distal sciatic nerves determined by immunohistochemistry to desmin was significantly reduced in the cisplatin compared with that of the control groups. Electron microscopic analysis demonstrated the detachment of pericytes from endothelial cells including the disruption of shared basement membrane in the sciatic nerves from cisplatin-treated rats. These data indicate the pericyte loss and detachment caused by cisplatin. Future studies of the BNB components and functions after cisplatin treatment are needed and will be essential for the development of effective treatments against cisplatin-induced neuropathy.

El cisplatino es un agente antineoplásico y presenta como uno de sus principales efectos secundarios, la neuropatía. Sin embargo, falta un tratamiento eficaz. La creciente evidencia sugiere que el cisplatino podría dañar los capilares nerviosos, lo que puede provocar una alteración de las funciones de la barrera hematoencefálica (BHE) y neuropatía. Este estudio tuvo como objetivo examinar los efectos del cisplatino en los pericitos. Las ratas se trataron con inyección intraperitoneal de cisplatino (2 mg/kg) dos veces por semana durante 5 semanas seguidas. Las ratas tratadas con cisplatino mostraron una reducción del peso corporal, hipoalgesia térmica y una velocidad de conducción del nervio ciático lenta, lo que indicaría neuropatía. La densidad de los pericitos en los nervios ciáticos distales determinada por inmunohistoquímica para desmina se redujo significativamente en el grupo cisplatino en comparación con la de los grupos controles. El análisis al microscopio electrónico demostró el desprendimiento de pericitos de las células endoteliales, incluida la ruptura de la membrana basal compartida en los nervios ciáticos de ratas tratadas con cisplatino. Estos datos indican la pérdida de pericitos y el desprendimiento causado por el cisplatino. Se necesitan estudios futuros de los componentes y funciones del BHE después del tratamiento con cisplatino y serán esenciales para el desarrollo de tratamientos efectivos contra la neuropatía inducida por el cisplatino.

Anatomy of osterior antebrachial cutaneous nerve related to the lateral epicondyle and interepicondylar line / Anatomía del nervio cutáneo posterior del antebrazo relacionado con el epicóndilo lateral y la línea interepicondilar

Posterior antebrachial cutaneous nerve (PACN) is a branch of radial nerve supplying the skin of posterior forearm. Data regarding its anatomy remain insufficient especially the origin and number of branches. We dissected 101 upper extremities from 32 male and 20 female cadavers to expose the PACN. In all specimens, the nerve emerged from the deep fascia at the hiatus proximal to the interepicondylar line (IEL) with mean distances of 7.24 and 7.44 cm in males and females, respectively. Percentage of this distance to the arm length was 23.2 % and 26.1 % in males and females, respectively. After penetrating the deep fascia, the PACN coursed in the subcutaneous layer and crossed the IEL anterior to the lateral epicondyle (LE) in all cases. The mean distances from the crossing point to the LE along the IEL were 1.52 cm in males and 1.34 cm in females. Regarding the branches of PACN, at least 50 % of the specimens had up to 3 or 4 branches originating either proximal or distal to the hiatus. In two arms, one of these branches passed posterior to the LE. Moreover, there were communicating branches between the PACN and the lateral antebrachial cutaneous nerve in 9 specimens. Gender and side differences were found in some measurement parameters. These data are crucial for avoiding the PACN injury during surgical procedures around the elbow.

El nervio cutáneo posterior del antebrazo (NCPA) es un ramo del nervio radial que inerva la piel del antebrazo. Los datos acerca de su anatomía siguen siendo insuficientes en especial en cuanto a su origen y el número de ramos. Disecamos 101 miembros superiores de cadáveres pertenecientes a 32 hombres y 20 mujeres para exponer el NCPA. En todas las muestras, el nervio surgió de la fascia profunda en el hiato proximal a la línea interepicondilar (LIE) con distancias medias de 7,24 y 7,44 cm en hombres y mujeres, respectivamente. El porcentaje de esta distancia a la longitud del brazo fue 23,2 % y 26,1 % en hombres y mujeres, respectivamente. Después de penetrar la fascia profunda, el NCPA continuaba en el tejido subcutáneo y cruzaba la LIE anterior al epicóndilo lateral (EL) en todos los casos. Las distancias medias desde el punto de cruce del EL a lo largo de la LIE fueron 1,52 cm en hombres y 1,34 cm en mujeres. Con respecto a las ramos del NCPA, al menos 50 % de las muestras tenían hasta 3 o 4 ramos, ya fuesen proximales o distales al hiato. En dos de los brazos, uno de estos ramos pasó posterior al EL. Por otra parte, en 9 de las muestras se observó comunicación entre los ramos del NCPA y el nervio cutáneo antebraquial lateral. No se encontraron diferencias secundarias o de sexo en algunos parámetros de medición. Estos datos son esenciales para evitar las lesiones durante los procedimientos quirúrgicos alrededor del codo que involucren el NCPA.

Anatomy of the sural nerve related to calcaneal tendon, intermalleolar line and small saphenous vein / Anatomía del nervio sural en relación con el tendón calcáneo, la línea intermaleolar y la vena safena parva

Sural nerve (SN) courses from the posterior aspect of leg to the lateral side of ankle and foot. Anatomy of the SN is of clinical importance due to its involvement in nerve biopsy, nerve graft harvesting including injuries during calcaneal tendon repair. Despite substantial knowledge in the literature, more easily located landmarks and data regarding the symmetry are still needed. Ninety-eight lower extremities from 31 males and 18 females were dissected in this study. The SN originated from the union between the medial and lateral sural cutaneous nerves in 52.0 % of the legs. The distance from the union point to the intermalleolar line (IML) was 16.3±8.4 (SD) cm. The ratio of this distance to the fibular length (apex of head to lateral malleolus or LM) was 0.47±0.23 cm. In 84.7 % of the legs, the SN initially coursed medial to and then crossed the lateral border of calcaneal tendon at the distance of 8.4±2.1 cm above the IML. The ratio to the fibular length was 0.25±0.06 cm. At the level of IML, the SN was posterior to the most prominent part of the LM in 95.9 % of the legs with the distance of 2.6±0.5 cm. At the closest point, the SN was lateral to the small saphenous vein in 74.5 % of the legs and the distance from this point to the IML was 10.6±4.7 cm. The ratio to the fibular length was 0.31±0.14 cm. Side difference or asymmetry was observed in a substantial number of specimens. These data are crucial for not only localizing the SN during biopsy and graft harvesting but also avoiding the nerve injury during relevant surgical procedures.

El nervio sural (NS) transcurre por la región posterior de la pierna, el tobillo y el pie. La anatomía del NS es de importancia clínica durante la realización de una biopsia, el desarrollo de injerto de nervio, incluyendo lesiones del nervio durante la reparación del tendón calcáneo. A pesar del conocimiento sustancial en la literatura, aún se necesitan puntos de referencia más fáciles de localizar e información sobre la simetría. Noventa y ocho miembros inferiores de 31 hombres y 18 mujeres fueron disecados. El NS se originó a partir de la unión entre los nervios cutáneo sural medial y cutáneo sural lateral en el 52,0 % de las piernas. La distancia desde el punto de unión a la línea intermaleolar (IML) fue de 16,3±8,4 (SD) cm. La relación de esta distancia a la longitud de la fíbula (vértice de la cabeza al maléolo lateral o LM) fue de 0,47±0,23 cm. En el 84,7 % de las piernas, el NS se ubicó inicialmente medial y luego cruzó el margen lateral del tendón calcáneo a una distancia de 8,4±2,1 cm proximal a la IML. La relación de longitud de la fíbula fue de 0,25±0,06 cm. A nivel de la IML, el NS se localizaba posterior a la parte más prominente de la LM en el 95,9 % de las piernas, con una distancia de 2,6±0,5 cm. En el punto más cercano, el NS se localizaba lateral a la vena safena parva en 74,5 % de las piernas y la distancia desde este punto hasta la IML fue de 10,6±4,7 cm. La relación de longitud de la fíbula fue 0,31±0,14 cm. La diferencia entre los lados o asimetría se observó en un número considerable de ejemplares. Estos datos son esenciales no sólo para localizar el NS durante la biopsia y la realización del injerto sino también para evitar la lesión del nervio durante procedimientos quirúrgicos relevantes.

Medial antebrachial cutaneous nerve: anatomical relationship with the medial epicondyle, basilic vein and brachial artery / Nervio cutáneo antebraquial medial: relación anatómica con el epicóndilo medial, vena basílica y arteria braquial

Medial antebrachial cutaneous nerve (MACN) courses in the medial arm to provide sensory innervation to the medial forearm. Its anatomy has been partly described since data regarding its branching pattern and distances to adjacent landmarks are still lacking. The purpose of this study was to provide morphometric anatomy of the MACN with comparisons between sides and sexes. Ninety-six upper extremities from 26 males and 22 females were dissected. We found that up to 5 branches of MACN pierced the deep fascia with the maximum of 4 reaching the interepicondylar line (IEL). Presence of 2 and 3 branches was found in the majority of cases (> 80%). The distances from these branches to the landmarks varied considerably. In case of no branch, the mean distances to the medial epicondyle (ME) and brachial artery (BA) were approximately 1.5 cm while those to the basilic vein (BV) were 0.7 cm in both sexes. Regardless of the branching pattern, the MACN could pass over or close (within 0.5 cm) to the ME, BV and BA. Asymmetry in the branching pattern was found in 50% of specimens. Sex but not side differences were observed in some measurement parameters. These data are crucial for not only localizing the MACN during nerve block and graft harvest but also avoiding the nerve injury during surgical procedures.

El recorrido del nervio cutáneo antebraquial medial (NCAM) proporciona la inervación sensorial medial del antebrazo. Su anatomía se ha descrito en parte, porque los datos relativos a su patrón de ramificación y distancias a puntos de referencia adyacentes son insuficientes. El propósito de este estudio fue proporcionar datos morfométricos sobre la anatomía del NCAM, comparando entre lados y sexos. Se disecaron 96 miembros superiores de 26 hombres y 22 mujeres. Se encontró que 5 ramos del NCAM traspasaron la fascia profunda y llegaron 4 hasta la línea interepicondilar (LIE). Presencia de 2 y 3 ramos se encontró en la mayoría de los casos (>80%). Las distancias de estos ramos a los puntos anatómicos variaron considerablemente. En caso de ausencia de ramos, la distancia medial al epicóndilo medial (EM) y arteria braquial (AB) fueron de aproximadamente 1,5 cm, mientras que a la vena basílica (VB) fueron 0,7 cm en ambos sexos. Independientemente del patrón de ramificación, el NCAM podría pasar sobre o cerca (a menos de 0,5 cm ) del EM, VB y AB. Asimetría en el patrón de ramificación se encontró en 50% de las muestras. Diferencias en algunos de los parámetros de medición se observaron según sexo, pero no por lado. Estos datos son relevantes para localizar el NCAM durante el bloqueo del nervio y la toma de injertos, sino también para evitar la lesión del nervio durante los procedimientos quirúrgicos.

Sartorial branch of saphenous nerve: anatomical relationship with bony landmarks and great saphenous vein / Ramo sartorial del nervio safeno safeno: relación anatómica con puntos de referencia óseos y de la vena safena magna

Sartorial branch of saphenous nerve (medial crural cutaneous nerve) originates at the medial side of the knee and descends along the great saphenous vein (GSV) to innervate the medial aspect of the leg. Its anatomy is of concern in surgical procedures and anesthetic block. However, the measurement data related to palpable bony landmarks with comparison between sexes and sides are lacking. Dissection was done in 95 lower limbs from both sexes. We found that the nerve pierced the deep fascia alone in most cases (92.6%). This piercing point was always distal to the adductor tubercle with the distance of 5-6 cm which was 15% of the leg length (the distance between the adductor tubercle and medial malleolus). The nerve was 7 cm medial to the tibial tuberosity. At the mid-level of leg length, the nerve was slightly over 4 cm medial to the anterior tibial margin. The nerve terminally divided 7 cm proximal to the medial malleolus. Furthermore, the anatomical relationship between the nerve and the GSV was highly variable. The nerve was constantly anterior, posterior or deep to the GSV in 8.4%, 15.8% and 2.1%, respectively. Crossing between the two structures was observed in 57.9% of specimens and the distance to the medial malleolus was 18 cm. Symmetry was found in most parameters and significant gender differences were observed in some distances. These results are important for avoiding the sartorial nerve injury and locating the nerve during relevant procedures.

El ramo sartorial del nervio safeno (nervio cutáneo medial de la pierna) se origina en el lado medial de la rodilla y desciende a lo largo de la vena safena magna (VSM) para inervar la cara medial de la pierna. Su anatomía es motivo de preocupación en los procedimientos quirúrgicos y en el bloqueo anestésico. Sin embargo, los datos de medición relacionados con puntos de referencia óseos palpables y la comparación entre los lados y en ambos sexos son escasas. Se realizó la disección en 95 miembros inferiores de ambos sexos. Se encontró que el nervio perforó la fascia profunda en la mayoría de los casos (92,6%). Esta punta de perforación fue siempre distal al tubérculo del músculo aductor magno a una distancia de 5-6 cm, que representaba el 15% del largo de la pierna (la distancia entre el tubérculo del aductor magno y el maléolo medial). El nervio se localizaba 7 cm medial a la tuberosidad tibial. Al nivel del tercio medio en ambas piernas, el nervio estaba a una distancia un poco mayor a 4 cm medial al margen anterior de la tibia. El nervio se dividía 7 cm proximal al maléolo medial. Por otra parte, la relación anatómica entre el nervio y la VSM fue muy variable. El nervio era constantemente anterior, posterior o profundo a la VSM en 8,4%, 15,8% y 2,1%, respectivamente. Cruce entre las dos estructuras anatómicas se observó en el 57,9% de las muestras y la distancia hasta el maléolo medial fue de 18 cm. La simetría se encuentra en la mayoría de los parámetros y diferencias de sexo significativas se observaron en algunas distancias. Estos resultados son importantes para evitar la lesión del nervio sartorial y localizar el nervio durante los procedimientos pertinentes.

Ganglioside GM1 (porcine) ameliorates paclitaxel-induced neuropathy in rats.

BACKGROUND: Paclitaxel, an anti-neoplastic agent effective against several solid tumors, has several side effects including peripheral neuropathy. So far, there are no effective treatments for this complication. Monosialic acid ganglioside (GM1) has been shown to protect neurons against injuries and degeneration. However, its efficacy in the treatment of paclitaxel-induced neuropathy has not been verified. OBJECTIVE: To evaluate the effect of porcine GM1 on neurophysiological abnormalities in rats receiving paclitaxel. MATERIAL AND METHOD: Fifty-four Wistar rats were divided into control, vehicle for paclitaxel (Cremophor EL), paclitaxel, and paclitaxel + GM1 groups. Paclitaxel 16 mg/kg/week for five consecutive weeks was given intraperitoneally. Treatment with 30 mg/kg 5 days per week of GM1 was started 3 days prior to the first dose and continued until 3 days after the last dose of paclitaxel. Tail and hind paw thermal thresholds including tail motor nerve conduction velocity (MNCV) were measured prior to and after the start of treatments. Histopathology of the sciatic nerve was also examined. RESULTS: Paclitaxel alone induced thermal hypoalgesia and reduced tail MNCV Less severe abnormalities were also found with the vehicle. GM1 appeared to prevent the development of hypoalgesia and ameliorated the decreased MNCV without any evidence of Guillain-Barre Syndrome. Mild endoneurial edema and axonal degeneration in the sciatic nerve sections were seen in paclitaxel treated rats. Microtubule accumulation and activated Schwann cell were also presented in the paclitaxel treated groups. CONCLUSION: These data suggest that porcine GM1 may be useful in the prevention and treatment of paclitaxel-induced neuropathy. However the adverse effect of Cremophor EL should be of concern.

Surgical anatomy of fissures and foramina in the orbits of Thai adults.

BACKGROUND: The anatomy of orbital foramina appears to vary depending on the population studied Moreover; different data between sides and genders have been reported. OBJECTIVE: The present study was done to provide the morphometric data of the orbitalforamina related to side and gender in Thai subjects. MATERIAL AND METHOD: One hundred orbits from 50 adult dried skulls were used. Gender of each skull was identified and the distances from the constant landmarks to the foramina in the medial, superior; inferior and lateral walls were measured. RESULTS: In the medial wall, the mean distances from the anterior lacrimal crest to the optic canal (OC), anterior, and posterior ethmoidalforamina were 42.2, 23.5, and 36. 0 mm for both sides and genders, respectively. The average distances from the supraorbital notch/foramen in the roof to the superior orbital fissure (SOF), OC, and lacrimal foramen were 44.7, 40.0, and 33.6 mm, respectively. In the inferior wall, the distances from the infraorbital rim to the OC, inferior orbital fissure (IOF), and the posterior edge of roof of the infraorbital canal were 46.2, 21.7, and 12.3 mm, respectively. The distances from the frontozygomatic suture to the OC, SOF, IOF and LF were 46.9, 34.5, 24.0, and 27.2 mm, respectively. When compared to those of the previous reports, several considerable differences that may be of clinical importance were observed. Moreover, some distances were significantly different between sides or genders. CONCLUSION: The present results suggest that race, side, and gender should be concerned during the orbital surgery and the data are good references for Thai subjects.

Anatomic characteristics and surgical implications of the superficial radial nerve.

BACKGROUND: Superficial radial nerve (SRN) that lies superficially on the radial side of the distalforearm and dorsum of the hand, can be injured by various procedures. Thus, precise knowledge in its variation is crucial. OBJECTIVE: Since there were no such data in Thai population, provide the variation data of the SRN in Thai cadavers. This is likely to be more accurate when applied in Thailand. MATERIAL AND METHOD: The authors studied the branching pattern and the course of SRN in 40 Thai cadavers. RESULTS: The extra type, replacement of SR3 by a branch of the lateral antebrachial cutaneous nerve, was found (4.7%) and the incidences of other patterns were different from those of previous reports. Moreover; asymmetry and gender difference were also demonstrated. The authors observed the higher frequencies of the SRN lying over the snuff box and first dorsal compartment of the wrist compared to other reports. The distances to important landmarks were measured and the presented data were comparable to those of other studies with no significant differences between sides or genders. CONCLUSION: These findings suggest that the different variations of the SRN among various races should be concerned during the relevant procedures.

Cadaver donation: a retrospective review at the King Chulalongkorn Memorial Hospital, Bangkok.

Cadavers are a crucial resource for medical education. Currently, donation is the only means of obtaining cadavers for use in Thai medical schools. Some traditional beliefs result in an insufficient number of donated cadavers. This shortage of cadavers may affect the quality of medical training. We report on the present situation regarding the quantity and usage of donated cadavers in the King Chulalongkorn Memorial Hospital, Bangkok, during the eight years between 1993 and 2000. During this period, 19,674 cadavers became available (2.459.3 +/- 1,243.7 cadavers/year) as the result of advanced donation. However, only 619 cadavers (3.1%) were actually obtained. Poor preservation and delayed delivery contributed to the underutilization; furthermore, some cadavers were reclaimed. In order to increase the number of cadavers and maintain the quality of medical education, the appropriateness and importance of cadaver donation should be emphasized to the public.