Structure and histology of extrafloral nectaries of tropical species in a mexican rain forest / Estrutura e histologia dos nectarios extraflorais de especies em uma floresta tropical no México

Although there is a large diversity of plant species with extrafloral nectaries, histological detail of these glands is poorly documented in tropical rain forest species. We characterized extrafloral nectaries using digital photographs, scanning electron microscopy and histological methods for eight plant species belonging to the Costaceae, Euphorbiaceae, Malvaceae and Salicaceae. To our knowledge, there are no previous reports on the structure of extrafloral nectaries for these species. Croton species exhibited reddish extrafloral nectaries on the petioles, surrounded by starshaped trichomes. Cnidoscolus multilobus and Omphalea oleifera showed green, elevated, extrafloral nectaries at the peduncle; C. multilobus showed abundant secretory tissue; O. oleifera revealed numerous cells with calcium oxalate crystals. Heliocarpus species showed extrafloral nectaries distributed at the base of the blade and possesses glands in the center of the extrafloral nectary surrounded by a series of parenchymatic cells. Pleuranthodendron lindenii has two extrafloral nectaries at the base of the leaves. Costus scaber has a hollow-type extrafloral nectary on the red-colored bracts of the inflorescence; nectar cavity is found in the center area of each bracts located on a yellow line. The extrafloral nectaries described in this study exhibited different morphologies and histological structures involved in the secretion of extrafloral nectar that could be related to biotic defenses, primarily by attracting ants.

Embora exista uma grande diversidade de espécies de plantas com nectários extraflorais, detalhes histológicos destas glândulas ainda é pouco documentado para espécies tropicais. Nós caracterizamos nectários extraflorais usando fotografias digitais, microscopia eletrônica de varredura e métodos histológicos para oito espécies de plantas das famílias Costaceae, Euphorbiaceae, Malvaceae e Salicaceae. Para nosso conhecimento, não há relatos anteriores sobre a estrutura dos nectários extraflorais para as espécies estudadas. Espécies de Croton exibiram nectários extraflorais avermelhadas nos pecíolos, rodeados por tricomas em forma de estrela. Cnidoscolus multilobus e Omphalea oleifera apresentaram nectários extraflorais verdes e elevados nos pedúnculos; C. multilobus apresenta tecido secretor abundante enquanto que O. oleifera apresentou numerosas células com cristais de oxalato de cálcio. Espécies de Heliocarpus apresentaram nectários extraflorais distribuídos na base da lâmina e possuíam glândulas no centro do nectário rodeadas por uma série de células de parênquima. Pleuranthodendron lindenii apresentou dois nectários extraflorais na base das folhas. Costus scaber apresenta um nectário extrafloral do tipo oco nas brácteas avermelhadas da inflorescência, e a cavidade do nectário se encontra na área central de cada bráctea localizados em uma linha amarela. Os nectários extraflorais descritos neste estudo apresentaram morfologia e estruturas histológicas diferentes envolvidas na secreção de néctar extrafloral que poderia estar relacionado com defesas bióticas, principalmente atraindo formigas.

Resultados de biopsia guiada por tomografía axial computarizada en el síndrome de destrucción vertebral, evaluados en dos instituciones distintas / Resultados de biópsia guiada por tomografia computadorizada axial na síndrome de destruição vertebral, avaliados em duas instituições distintas / Results of computerized axial tomography-guided biopsy in the vertebral destruction syndrome, evaluated at two different institutions

OBJETIVO: Comparar resultados de biopsias vertebrales guiadas por tomografía axial computarizada, reportados por dos servicios de Anatomía Patológica distintos en pacientes con síndrome de destrucción vertebral para confirmar confiabilidad y utilidad en el diagnóstico. MÉTODOS: Se obtuvieron muestras de tejido de 21 pacientes en el periodo comprendido del 1 de marzo al 15 de julio del 2011 con el diagnóstico del síndrome de destrucción vertebral y a quienes se les realizó biopsia guiada por tomografía axial computarizada. Las muestras se enviaron en forma cegada a dos servicios de patología distintos. Los resultados fueron analizados con el método de comparación de dos proporciones. RESULTADOS: 14 pacientes fueron del género masculino (67%) y 7 del femenino (23%), edades de 28-82, con afección principalmente lumbar (48%) y torácica (38%); afectados en una vértebra en 62%, en dos en un 33% y en 3 o más niveles en 5%. Las vértebras más afectadas fueron L1, L2 y L3 (12/30 [40%]), T4 (3/30 [10%]) y T9 (3/30 [10%]). Los resultados se agruparon en categorías: 1. Osteomielitis (9/21 [43%]), 2. Tumores (7/21 [33%]), 3. Metástasis (3/21 [14%]), 4. Tejido normal (2/21 [10%]), 5. Inflamación (0/21 [0%]), 6. Muestra inadecuada (0/21 [0%]), 7. Mal de Pott (0/21 [0%]). CONCLUSIONES: De acuerdo a los valores de Z obtenidos mediante la prueba de comparación de dos proporciones no se encontró diferencia significativa entre los resultados reportados por dos los dos servicios de patología en el síndrome estudiado, determinándose que esta parte del proceso es confiable y útil en un 90%.

OBJETIVO: Comparar resultados de biópsias vertebrais guiadas por tomografia axial computadorizada, relatados por dois serviços de Anatomia Patológica distintos em pacientes com síndrome de destruição vertebral para confirmar a confiabilidade e a utilidade no diagnóstico. MÉTODOS: Foram obtidas amostras de tecido de 21 pacientes no período de 1 de março a 15 de julho de 2011, com diagnóstico de síndrome de destruição vertebral, que foram submetidos a biópsia guiada por tomografia axial computadorizada. As amostras foram enviadas de modo cego a dois serviços de patologia distintos. Os resultados foram analisados pelo método de comparação de duas proporções. RESULTADOS: 14 pacientes eram do sexo masculino (67%) e 7 do feminino (23%), com idades entre 28 e 82 e afecção predominantemente lombar (48%) e torácica (38%); 62% tinham comprometimento em uma vértebra, 33% em duas e 5% em três ou mais níveis. As vértebras mais afetadas foram L1, L2 e L3 (12/30 [40%]), T4 (3/30 [10%]) e T9 (3/30 [10%]). Os resultados foram agrupados em categorias: 1. Osteomielite (9/21 [43%]), 2. Tumores (7/21 [33%]), 3. Metástases (3/21 [14%]), 4. Tecido normal (2/21 [10%]), 5. Inflamação (0/21 [0%]), 6. Amostra inadequada (0/21 [0%]), 7. Mal de Pott (0/21 [0%]). CONCLUSÕES: De acordo com os valores de Z obtidos pela prova de comparação de duas proporções, não se encontrou diferença significante entre os resultados relatados pelos dois serviços de patologia na síndrome estudada, ficando determinado que essa parte do processo tem confiabilidade e utilidade de 90%.

OBJECTIVE: To compare results of vertebral biopsy guided by computerized axial tomography scan, reported by two different Departments of Pathology in patients with vertebral destruction syndrome to confirm the reliability and utility in the diagnosis. METHODS: Tissue samples from 21 patients were obtained March 1 to July 15, 2011, with a diagnosis of the vertebral destruction syndrome and who underwent computerized axial tomography-guided biopsy. The samples were blindly sent to two different pathology services. The results were analyzed using the two-proportion z-test. RESULTS: 14 patients were male (67%) and 7 females (23%), aged between 28 and 82, with condition predominantly lumbar (48%) and thoracic (38%); 62% had one vertebra affected, 33% ha two and 5% had three or more levels involved. The most affected vertebrae were L1, L2 and L3 (12/30 [40%]) and T9 (3/30 [10%]). The results were grouped into categories: 1. Osteomyelitis (9/21 [43%]), 2. Tumors (7/21 [33%]), 3. Metastases (3/21 [14%]), 4. Normal tissue (2/21 [10%]), 5. Inflammation (0/21 [0%]), 6. Inadequate sample (0/21 [0%]), 7. Pott's disease (0/21 [0%]). CONCLUSIONS: According to the values obtained by the two-proportion z-test, there was no significant difference between the results reported by the two departments of pathology for the syndrome studied, being determined that this part of the process has reliability and usefulness of 90%.

Evaluacion de la biopsia transpedicular guiada por TAC / Avaliação da biópsia transpedicular guiada por TC / Evaluation of transpedicular percutaneous biopsy guided by CT

OBJETIVO: Valorar la utilidad de la biopsia transpedicular percutánea guiada por Tomografía Axial Computarizada en conjunto con la sistematización de estudios como pruebas diagnósticas de la etiología de la destrucción vertebral. MÉTODOS: Estudio de serie de casos prospectivo transversal de 21 pacientes a los que se les realizó biopsia transpedicular percutánea guiada por Tomografía Axial Computarizada y estudios de laboratorio y gabinete de marzo a julio del 2011, para evaluar su utilidad en el diagnóstico de destrucción vertebral. RESULTADOS: Fueron 21 pacientes, 14 hombres y 7 mujeres, con edad media de 59,2 años, cuyos niveles más afectados estuvieron en L1, L2 y L3. El reporte de la biopsia tuvo una precisión diagnóstica del 90,4%. En 2 casos se realizó correlación clínica entre biopsia y sistematización de estudios para obtener el diagnóstico. CONCLUSIÓN: La biopsia guiada por Tomografía Axial Computarizada es una técnica sencilla, útil, de bajo costo y eficaz en el estudio de la destrucción vertebral; la sistematización de estudios permite corroborar el diagnóstico de la biopsia.

OBJETIVO: Avaliar a utilidade da biópsia transpedicular percutânea guiada por tomografia axial computadorizada em conjunto com a sistematização de estudos, como exames diagnósticos da etiologia da destruição vertebral. MÉTODOS: Estudo de série de casos, prospectivo e transversal de 21 pacientes submetidos à biópsia transpedicular percutânea guiada por tomografia axial computadorizada e exames laboratoriais e radiológicos, de março a julho de 2011, para avaliar sua utilidade no diagnóstico de destruição vertebral. RESULTADOS: Foram analisados 21 pacientes, 14 homens e 7 mulheres, com média de idade de 59,2 anos, cujos níveis mais afetados foram L1, L2 e L3. O laudo da biópsia teve precisão diagnóstica de 90,4%. Em dois casos, realizou-se a correlação clínica entre biópsia e sistematização de exames para obter o diagnóstico. CONCLUSÃO: A biópsia guiada por tomografia axial computadorizada é uma técnica simples, útil, de baixo custo e eficaz para o estudo da destruição vertebral; a sistematização de estudos permite corroborar o diagnóstico da biópsia.

OBJECTIVE: To evaluate the usefulness of percutaneous transpedicular biopsy guided by CT together with systematic studies such as diagnostic tests of the etiology of vertebral destruction. METHODS: Case series, prospective and crossover study of 21 patients who underwent percutaneous transpedicular biopsy guided by CT and laboratory tests and radiological studies from March to July 2011, to evaluate its usefulness in the diagnosis of vertebral destruction. RESULTS: We analyzed 21 patients, 14 men and 7 women, mean age 59.2 years, whose most affected levels were L1, L2, and L3. The biopsy report had diagnostic accuracy of 90.4%. In 2 patients the clinical correlation between biopsy and systematization of diagnostic studies was carried out. CONCLUSION: CT-guided biopsy is a simple, useful, inexpensive, and effective technique for the study of vertebral destruction; the systematic studies allow us to corroborate the diagnosis made by biopsy.

Evaluación de una nueva sistematización de estudios para el diagnóstico del síndrome de destrucción vertebral / Avaliação de nova sistematização de exames para o diagnóstico da síndrome de destruição vertebral / Evaluation of a new systematization of tests for the diagnosis of vertebral destruction syndrome

OBJETIVO: Explorar la efectividad de un conjunto de pruebas de diagnósticos, sistematizadas en hoja de protocolo, para la determinación del Síndrome de Destrucción Vertebral en pacientes de nuestro servicio. MÉTODOS: Analizamos una propuesta de sistematización mediante un estudio piloto de 20 pacientes a quienes se realizaron 10 diferentes pruebas de laboratorio y gabinete, además del estudio histopatológico de biopsia percutánea. Se describieron las características demográficas y clínicas, con los resultados obtenidos mediante estadística descriptiva, media y desviación estándar para las variables cuantitativas y porcentajes para las cualitativas. RESULTADOS: Edad promedio de 53,3 años ± 16,56 años; 10 hombres y 10 mujeres. 30 vértebras afectadas en los 20 pacientes, 8 de ellos tuvieron afección de dos o más vértebras. El nivel más afectado fue el Lumbar en 18 casos, seguido por el Torácico en 12. El Mal de Pott se diagnosticó en 7 casos (35%), Osteomielitis en 4 (20%), Mieloma Múltiple en 2 (10%), y Espondilodiscitis, Metástasis de Adenocarcinoma, Linfoma y Osteoporosis en un caso respectivamente (5%). En 3 casos (15%) no se obtuvo un diagnóstico específico. CONCLUSIONES: Esta propuesta de sistematización fue útil para llegar al diagnóstico etiológico definitivo del SDV en 85% de los casos, con la reducción en la cantidad de estudios realizados. Es necesario mayor número de pacientes para aumentar la evidencia de su utilidad.

OBJETIVO: Explorar a efetividade de um conjunto de exames diagnósticos sistematizados em folha de protocolo para determinação da síndrome de destruição vertebral em pacientes atendidos em nosso serviço. MÉTODOS: Analisamos uma proposta de sistematização por meio de estudo piloto de 20 pacientes que foram submetidos a dez exames laboratoriais e de imagens distintos, além do estudo histopatológico de biópsia percutânea. Foram descritas as características demográficas e clínicas e os resultados foram obtidos por estatística descritiva, média e desvio padrão para as variáveis quantitativas e porcentagens para as qualitativas. RESULTADOS: Média de idade de 53,3 ± 16,56 anos; 10 homens e 10 mulheres. Trinta vértebras afetadas nos 20 pacientes; 8 deles tinham afecção em duas ou mais vértebras. O nível mais afetado foi o lombar em 18 casos, seguido pelo torácico em 12. A tuberculose da coluna vertebral (doença de Pott) foi diagnosticada em 7 casos (35%), a osteomielite, em 4 (20%), o mieloma múltiplo, em 2 (10%) discite, metástase de adenocarcinoma, linfoma e osteoporose, cada um em um caso (5%). Em 3 casos (15%) não se obteve diagnóstico específico. CONCLUSÕES: Esta proposta de sistematização foi útil para chegar ao diagnóstico etiológico definitivo da SDV em 85% dos casos, com redução da quantidade de exames realizados. É preciso estudar um número maior de pacientes para aumentar a evidência de sua utilidade.

OBJECTIVE: To explore the effectiveness of a systematic set of diagnostic tests in a protocol sheet for determination of vertebral destruction syndrome in patients treated in our service. METHODS: We analysed a proposal for systematization through a pilot study of 20 patients who underwent 10 different laboratory and imaging tests, as well as the histopathological study through percutaneous biopsy. We described the demographic and clinical characteristics and likewise the results obtained by means of descriptive statistics, mean and standard deviation for quantitative variables and percentage for qualitative variables. RESULTS: Average age of 53.3 ± 16.56 years; 10 men and 10 women. Thirty vertebrae affected in 20 patients; 8 patients had disease in two or more vertebrae. The most affected level was the lumbar in 18 cases, followed by thoracic in 12. The spinal tuberculosis (Pott's disease) was detected in 7 cases (35%), osteomyelitis in 4 (20%), multiple myeloma, in 2 (10%), and discitis, metastasis of adenocarcinoma, lymphoma and osteoporosis in one case (5%). In 3 cases (15%) there was no specific diagnosis. CONCLUSIONS: This proposal of systematization was useful to reach the final etiological diagnosis of the VDS in 85% of cases, with the reduction in the number of tests. It is necessary to study a larger number of patients to increase the evidence of its usefulness.

Resonancia magnética nuclear en el postoperatorio de discectomía lumbar en pacientes asintomáticos y con síndrome de cirugía lumbar fallida / Ressonância nuclear magnética no pós-operatório da discectomia lombar em pacientes assintomáticos e com síndrome de cirurgia lombar falida / Nuclear magnetic resonance in postoperative lumbar discectomy in asymptomatic patients and with failed back surgery syndrome

OBJETIVO: analizar los cambios posquirúrgicos en pacientes sometidos a discectomía lumbar, tanto en pacientes cuya evolución ha sido satisfactoria, como en aquellos con "Síndrome de Cirugía Lumbar Fallida", enfatizando el justo valor que la resonancia magnética nuclear tiene. MÉTODOS: el universo de trabajo está constituido por dos grupos: Grupo I, cinco pacientes con evolución satisfactoria, asintomáticos; y Grupo II con diez pacientes con resultados considerados no satisfactorios y/o Síndrome Fallido Lumbar. Se analizaron los resultados obtenidos en la imagen de resonancia magnética nuclear, emitiendo un diagnóstico con evaluación externa sin conocimiento del estado clínico de los pacientes. También se realizó la correlación con el estado clínico en ambos los grupos. RESULTADOS: las manifestaciones clínicas preoperatorias tuvieron una distribución muy similar. En ninguno de los dos grupos se reportaron complicaciones transoperatórias. En todos se estudió por histopatología y se reportó disco degenerado o hialinizado. En el Grupo I, no se encontró imagen de alguna anomalía a pesar de su estado clínico. En todos los pacientes se encontraron datos de fibrosis posquirúrgica; en cuatro casos, disco residual con compresión radicular en los cinco pacientes. En el Grupo II, sólo en ocho pacientes, la resonancia magnética nuclear demostró algún hallazgo anormal. Los hallazgos anormales fueron: fibrosis posquirúrgica en cinco casos (50 por ciento), disco residual en tres casos (30 por ciento) y datos de compresión radicular en seis de los casos (60 por ciento). CONCLUSIÓN: no hay congruencia entre los hallazgos de resonancia magnética nuclear y la clínica, en pacientes postoperados de discectomía lumbar con evolución satisfactoria, hasta el momento, asintomáticos. La resonancia magnética nuclear no es confiable en estos pacientes.

OBJETIVO: analisar as mudanças pós-cirúrgicas nos pacientes submetidos à discectomia lombar em pacientes com evolução satisfatória, assim como naqueles com "Síndrome de Cirurgia Falida", dando ênfase ao justo valor que a ressonância nuclear magnética tem. MÉTODOS: o universo do trabalho esta constituído por dois grupos, Grupo I com cinco pacientes com evolução satisfatória, assintomáticos. O Grupo II possui dez pacientes com resultados considerados não-satisfatórios e/ou "Síndrome Falida Lombar". Analisaram-se os resultados obtidos na imagem da ressonância nuclear magnética, emitindo um diagnóstico com avaliação externa sem conhecimento do estado clínico dos pacientes, e realizou-se uma correlação com o estado clínico de ambos os grupos. RESULTADOS: as manifestações clínicas pré-operatórias tiveram uma distribuição muito similar. Em nenhum dos grupos se reportaram complicações transoperatórias. Em todos os grupos, foi feito o estudo histopatológico e foi informado o disco degenerado ou hialinizado. No Grupo I, não foi encontrada imagem de alguma anomalia apesar de seu estado clínico. Em todos os pacientes foram encontrados dados de fibroses pós-cirúrgica, em quatro casos, disco residual, com compressão radicular nos cinco pacientes. No Grupo II, só foi possível encontrar em oito pacientes, e a ressonância nuclear magnética demonstrou algum achado anormal, os quais foram fibroses pós-cirúrgica, em cinco casos (50 por cento); disco residual, em três casos (30 por cento); e dados de compressão radicular, em seis casos (60 por cento). CONCLUSÃO: não há congruência entre os achados da ressonância nuclear magnética e a clínica em pacientes pós-operatórios da discectomia lombar com evolução satisfatória, até o momento, assintomáticos. A ressonância nuclear magnética não é confiável nestes pacientes.

OBJECTIVE: to analyze the postoperative changes in patients undergoing lumbar discectomy, both in patients whose evolution has been satisfactory, as in those with "Failed lumbar Surgery Syndrome", emphasizing the fair value that the nuclear magnetic resonance has. METHODS: the work environment consists of two groups: Group I, five patients with satisfactory evolution and asymptomatic. Group II is composed of ten patients with unsatisfactory results and/or Failed Lumbar Syndrome. The results obtained in the nuclear magnetic resonance image were analyzed, emitting a diagnosis with external evaluation without knowledge of the clinical status of patients, and a correlation with clinical status in both groups was performed. RESULTS: the clinical preoperative manifestations had a very similar distribution. Transoperatory complications were not reported in any of the two groups. In all the groups, the histopathology study was carried out and it was reported the disk degenerated or hyalinization. In Group I, it was not found any abnormality, despite its clinical state. In all the patients, postoperative fibrosis data was found in four cases, and residual disk root was compressed in five patients. In Group II, only in eight patients, the nuclear magnetic resonance showed abnormal findings. The abnormal findings were: fibrosis postoperative in five cases (50 percent), residual disk in three cases (30 percent), and data root compression in six cases (60 percent). CONCLUSION: there is no congruence between the nuclear magnetic resonance and clinic findings, in postoperative patients, of lumbar disectomy with a satisfactory development, who, so far, are asymptomatic. The nuclear magnetic resonance is not reliable in these patients.

Tumor de vaina nerviosa periférica maligno asociado a neurofibromatosis tipo 1: informe de dos casos / Malignant peripheral nerve sheath tumors associated with neurofibromatosis type 1: report of two clinical cases

Introducción: El tumor de vaina nerviosa periférica maligno (TVNPM) es un sarcoma de alto grado de malignidad, originado de componentes de las vainas nerviosas, fibroblastos, células perineurales y células de Schwann, que se asocia a neurofibromatosis tipo 1 con un riesgo de 10 a 13 %. Casos clínicos: Se presentan dos casos de TVNPM asociado a neurofibromatosis tipo 1. El primero presentó dolor moderado sin causa aparente, además de lesión intrarraquídea en resonancia magnética nuclear, manejada quirúrgicamente en dos ocasiones. Histológicamente correspondió a lesión neurofibromatosa en transición con neoplasia maligna. El segundo se manifestó con cifoescoliosis torácica, dolor y aumento de volumen. Asociado a la deformidad, la resonancia magnética mostró tumor en la región torácica posterior (T1 a T8), que fue resecado; se identificó neoplasia sarcomatosa infiltrante, muy celular, con inmunopositividad para proteína S100 y vimentina. Conclusiones: Los TNVPM son sarcomas con alto índice de recurrencia, capaces de producir metástasis a distancia desde etapas tempranas. A pesar de la resección amplia, los pacientes descritos no sobrevivieron dado el avance y tamaño de las lesiones. Por el crecimiento progresivo de los TNVPM y la dificultad anatómica para su abordaje, deberá tenerse un control estrecho de los pacientes con neurofibromatosis tipo 1 a fin de identificar tempranamente la transformación maligna de las lesiones.

BACKGROUND: Malignant peripheral nerve sheath tumor (MPNST) is a sarcoma with a high grade of malignancy originating in the nerve sheath components, fibroblasts, perineural cells, and Schwann cells. It is associated with neurofibromatosis type 1 (NF-1) with a risk of 10-13%. CLINICAL CASES: We present two cases of NF-1-associated MPNST. The first patient presented moderate pain with no apparent cause, in addition to the presence of intraspinal lesion demonstrated by nuclear magnetic resonance imaging (NMRI), which was managed surgically on two occasions. Histologically, it corresponded to a neurofibromatosis lesion in transition with malignant neoplasm. The second case manifested with thoracic kyphoscoliosis, pain, and an increase in volume. Associated with the deformity, MRI showed a withering tumor in the posterior thoracic region (T1-T8), observing an infiltrating, cellular sarcomatous neoplasm with immunopositivity for S-100 protein and vimentin. CONCLUSIONS: MPNSTs are sarcomas with a high index of recurrence with the ability to produce distant metastasis during early stages. Despite wide resection, patients did not survive due to the advancement and size of the lesions (determining factors in the prognosis). Due to the progressive growth of MPNST and the anatomic difficulty for its approach, there should be strict surveillance of patients with NF-1 for early detection of malignant transformation in these lesions.

Hemangioma vertebral del arco posterior con extensión extraósea y sintomatología neurológica: informe de un caso y revisión de la literatura / Vertebral hemangioma of the posterior arch with subsequent extraosseous extension and neurological symptoms: case report and literature review

Introducción: El hemangioma vertebral es el tumor más común de la columna vertebral, se identifica hasta en 11 % de las autopsias. Es tipificado como una malformación benigna vascular de crecimiento lento; en ocasiones involucra los elementos posteriores, asociándose a compromiso neurológico. Por lo general es asintomático, encontrándose de forma incidental al estudiar el dolor de origen espinal en busca de otra patología; ocasionalmente produce manifestación neurológica. La extensión extraósea intrarraquídea con compromiso neurológico ha sido poco informada y representa un reto terapéutico. Caso clínico: Adolescente femenina con hemangioma vertebral de tamaño inusual del arco posterior con extensión hacia el conducto raquídeo que ocasionó manifestaciones neurológicas y ameritó tratamiento quirúrgico para su resección y fijación transpedicular. Conclusiones: El hemangioma vertebral es una lesión asintomática que no requiere tratamiento específico. Solo en algunos casos es necesario el tratamiento quirúrgico, que debe llevarse a cabo oportunamente cuando hay compresión neurológica, para evitar secuelas permanentes. El crecimiento extraóseo intrarraquídeo con deterioro neurológico es una presentación inusitada.

BACKGROUND: Vertebral hemangioma is the most common benign spinal tumor and is found in 11% of postmortem studies as a slow-growing benign vascular malformation. It usually involves the vertebral body and sometimes the posterior vertebral elements. When the posterior elements are involved, spinal cord compression with neurological symptoms are seen more often. Vertebral hemangiomas exist as a continuum of manifestations and lesions ranging from the common asymptomatic forms to the rare compression lesion. Extraosseous extension of vertebral hemangioma with cord compression and neurological symptoms is a rare condition and represents a treatment challenge. Surgical options are open resection, embolization or vertebroplasty. CLINICAL CASE: We report a case of a vertebral hemangioma with extraosseous extension to the spinal canal with an unusual size and osseous component in the posterior elements. This tumor caused neurological manifestations and was surgically treated with posterior decompression and stabilization with transpedicular screws and rods. Clinical outcome was good. CONCLUSIONS: Vertebral hemangioma is normally an asymptomatic benign lesion not requiring specific treatment. Only in a few cases is surgical treatment required. When neurological compromise is present, early treatment should be carried out before the presence of permanent paralysis.

Tumores intradurales extramedulares primarios tratados en el Instituto Nacional de Rehabilitación / Primary intradural extramedullary tumors treated at the National Institute of Rehabilitation (Mexico)

Introducción: Los tumores de la columna son lesiones poco comunes que afectan a una porción menor de la población, sin embargo, pueden causar morbilidad significativa y estar asociados a mortalidad. Representan 15 % de los tumores craneoespinales. El objetivo del presente trabajo fue definir la frecuencia de tumores intradurales extramedulares de columna vertebral en el Servicio de Cirugía de Columna Vertebral del Instituto Nacional de Rehabilitación, y su diagnóstico histopatológico definitivo. Material y métodos: Estudio retrospectivo de una serie de pacientes tratados quirúrgicamente entre 1996 y 2006 por diagnóstico de tumor intradural extramedular. Se evaluó sexo, edad, localización, sintomatología y tipo de tumor. Resultados: Se revisaron 27 pacientes, 11 hombres y 16 mujeres, con edad promedio de 47.33 años. Los síntomas principales fueron dolor y pérdida de la fuerza. La localización más frecuente fue la torácica seguida de la lumbar; el diagnóstico histopatológico indicó meningioma en 12 casos, schwannoma en 12 y neurofibroma en tres. Conclusiones: La sintomatología, localización y predominio de sexo son similares a los informados en la literatura. A diferencia de otras series, los tumores más frecuentes en la nuestra fueron schwannomas y meningiomas. Es importante el diagnóstico oportuno y tratamiento adecuado, que en nuestros pacientes consistió en resección total con laminoplastia, para evitar secuelas neurológicas permanentes.

BACKGROUND: Spine tumors are uncommon injuries affecting a low percentage of the population; however, these tumors can cause significant morbidity and may be related to mortality. They represent 15% of craniospinal tumors. The objective of this study is to determine the frequency of intradural extramedullary spine tumors treated in our Service and to report the definitive histopathological diagnosis. METHODS: This was a retrospective study in a series of patients treated surgically with a diagnosis of intradural extramedullary tumor in the Spine Service of the National Rehabilitation Institute (Mexico) from 1996 to 2006. The following variables were evaluated: gender, age, tumor localization, symptomatology and type of tumor. RESULTS: Files of 27 patients were reviewed. There were 11 men and 16 women with an average age of 47.33 years. The main symptoms were pain and motor weakness. The most frequent localization was thoracic followed by lumbar. Histopathological diagnosis reported 12 cases of meningioma, 12 cases of schwannoma and 3 cases of neurofibroma. CONCLUSIONS: Symptomatology, localization and gender predominance are similar to that reported in the literature. Different from other series, schwannomas and meningiomas were the most frequent tumors in our study. Appropriate diagnosis and opportune treatment consisting of total resection with laminoplasty are crucial in order to avoid permanent neurological consequences.

Resultado en el tratamiento quirúrgico de la inestabilidad atlantoaxoidea / Results of the surgical treatment of atlantoaxial instability

Introducción: La inestabilidad de la columna cervical es el aumento en la movilidad más allá de los límites fisiológicos de una vértebra sobre otra en alguno de sus ejes, que condiciona síntomas en el paciente. Existen causas traumáticas, degenerativas, metabólicas y neoplásicas. Material y métodos: Se realizó estudio retrospectivo, longitudinal, observacional y descriptivo, de intervención deliberada, en pacientes con cirugía por inestabilidad atlantoaxoidea, de enero de 1993 a mayo de 2002, con un seguimiento mínimo de cinco años. Resultados: Se evaluaron 11 pacientes, con edades de 25 a 75 años, media de 56 años. El sexo predominante fue el femenino. La etiología fue iatrogénica en seis casos, cuatro por artritis reumatoide y uno postraumática. En todos se realizó fijación y artrodesis occipitocervical con resección del arco posterior. El déficit neurológico preoperatorio predominante según la escala de Ranawat fue grado II, y en el posoperatorio fue grado I. Conclusiones: La edad media de nuestra serie fue discretamente menor respecto a la indicada en la literatura; el sexo predominante correspondió a lo informado en la literatura. Existió mejoría en ocho de los 11 pacientes, como en otras series. La mayor incidencia se observó entre los 30 y 64 años. La actividad ocupacional con mayor frecuencia fue la del hogar. El déficit neurológico según la escala de Ranawat mejoró en 72 % de los pacientes.

BACKGROUND: Instability of the cervical spine is defined as an increase in flexibility farther than the physiological limits of one vertebra over another in some of its axes, conditioning symptoms for the patient. Traumatic, degenerative, metabolic and neoplastic causes have all been identified. METHODS: A retrospective, longitudinal, observational and descriptive study was carried out on patients surgically intervened specifically for atlantoaxial instability from January 1993 to May 2002, with a minimum 5-year follow-up. RESULTS: Eleven patients were evaluated. Ages ranged from 25 to 75 years (average age 56 years) with a female predominance. Etiology was iatrogenic in six cases, and there were four cases of rheumatoid arthritis and one case due to trauma. In all cases, fixation was accomplished with occipitocervical arthrodesis with posterior arch resection. Predominant preoperative neurologic deficit according to Ranawat was grade II and postoperatively was grade I. CONCLUSIONS: The average age of patients in our series was discreetly lower in regard to what has been reported in the literature. Female predominance was in accordance with previous publications. Eight of 11 patients showed improvement as in other series. A higher impact was observed in patients between 30 and 64 years of age. The occupational activity with the highest frequency was homemaker, and the neurologic deficit according to Ranawat showed improvement in 72% of the patients.

Evaluación clínica y radiológica de la prótesis de núcleo discal Nubac: informe preliminar / Clinical and radiological follow-up of Nubac disc prosthesis: preliminary report

BACKGROUND: Lumbar arthroplasty is an alternative to fusion for the treatment of degenerative disc disease. Replacement of the nucleus pulposus preserves the biomechanical properties in the annulus and plates, conserving lumbar motion. Our objective was to evaluate the feasibility and clinical and radiological findings at 3 months follow-up with the Nubac device. METHODS: Ten patients from the National Institute for Rehabilitation (INR, Mexico City) with degenerative disc disease were selected to participate in the study. They underwent discectomy with Nubac device with a follow-up period of 3 months. Evolution was evaluated with the VAS and Oswestry scales. RESULTS: Five men and five women were included in the study (average age 41.6 years). Surgical approach was anterolateral (4 patients), posterior (3 patients) and anterior (3 patients), VAS improved from 8.1 to 2.5 (p <0.05) and Oswestry Disability Index (ODI) improved from 58.2% to 24.2% (p <0.05). Disc height before surgery was 9.4 mm, and 3 months postoperatively was 12.5 mm with no complications, migration, or subsidence. CONCLUSIONS: Nubac prosthesis improved lumbar discogenic pain in a short time when evaluated using ODI and VAS scales. Disc height improved after a 3-month follow-up, but lumbar motion did not improve. No complications have been reported; however, a minimum follow-up of 4 years is needed to make a definite conclusion.

Síndrome de destrucción vertebral: sistemas de evaluación en su diagnóstico / Vertebral destruction syndrome: diagnostic evaluation systems

BACKGROUND: Vertebral Destruction Syndrome (VDS) is a pathology of multiple etiologies causing structural alterations of the spine, producing deformity with neurological and mechanical alterations. In order to study VDS, a diagnostic process is carried out, sometimes with unexpected results. We undertook this study to validate the systematization of a series of studies to arrive at the diagnosis of VDS. METHODS: We included 105 patients in the study with diagnosis of VDS from January 1998 to December 2005, taking into consideration specificity, sensitivity and predictive value of each integrated study in order to determine its diagnostic value. RESULTS: The most frequent etiology was Pott's Disease (24 cases) followed by osteomyelitis (20 cases), metastasis (18 cases) and multiple myeloma and plasmacytoma (16 cases each). The higher sensitivity in Pott's Disease was obtained with bone scan and polymerase chain reaction (PCR); for multiple myeloma, computerized axial tomography (CAT) and bone scan; CAT and bone scan for infections; MRI for primary tumors; and MRI and bone scan for secondary tumors. CONCLUSIONS: To reduce false positives to 2% and to reduce the maximum number of false negatives, studies such as CAT, MRI, bone scan, PCR, ESR, C-reactive protein and determination of alkaline and acid phosphatase must be included in the VDS study protocol. Other studies have very low diagnostic sensitivity and specificity.

Evaluación de la biopsia percutánea en el diagnóstico del síndrome de destrucción vertebral tóracico y lumbar / Percutaneous biopsy evaluation in the diagnosis of thoracic and lumbar vertebral destruction syndrome

BACKGROUND: The vertebral destruction syndrome is defined as those pathologies affecting the integrity of the vertebral structure, modifying its normal architecture and resulting in neurological deficit. Correct diagnosis is essential to define appropriate treatment. Biopsy, in addition to histopathological study, is a vital element for definitive diagnosis. METHODS: We carried out a descriptive, deliberate interventional study in 20 patients with a diagnosis of vertebral destruction in whom a percutaneous transpendicular biopsy was done between January 2005 and July 2006. Variables analyzed were age, sex, affected segment, neurological condition, neurological deficit type, results of the biopsy and specific diagnosis. RESULTS: There was a predominance of males (55%). The lumbar spine was the most affected region in 80% of patients. Of the biopsies performed, 10% were reported as normal tissue, 20% with degenerative changes, 15% with inflammatory changes, 15% with primary tumoral lesion, 5% with chronic osteomyelitis, 10% with tuberculosis, 15% with tumoral metastasis and 10% necrotic devitalized bone tissue. Of these patients, 55% were treated nonsurgically, and the remaining 45% were treated surgically. No complications were reported. CONCLUSIONS: Percutaneous transpedicular biopsy has only 55% specificity in diagnosis and for that reason is a less useful diagnostic method in our setting for destructive lesion diagnosis from the vertebral body.

Quiste óseo aneurismático de la columna vertebral: reporte de un caso / Aneurysmal bone cyst of the spine: case report

El quiste óseo aneurismático es un tumor de naturaleza neoplásica indefinida, de comportamiento benigno, crecimiento rápido y ocasionalmente de comportamiento agresivo, cuyo tratamiento de elección es la resección completa, aunque existe el riesgo de sangrado transquirúrgico excesivo. Se presenta el caso de una paciente con deformidad en columna torácica, con parestesias y debilidad muscular progresivas en extremidades inferiores, que evolucionó hasta la parálisis de dichas extremidades e incontinencia de ambos esfínteres. Mediante estudios de gabinete se localizaron lesiones líticas en cuerpos vetebrales T7 a T9 e invasión a conducto raquídeo. Los estudios electrofisiológicos identificaron bloqueo completo de la vía somatosensorial. Previa biopsia incisional, se realizó resección de la lesión y estabilización de la columna toracolumbar. La paciente evolucionó sin mejoría de la función medular. Los hallazgos morfológicos correspondieron a quiste óseo aneurismático en T8. Esta lesión se localiza principalmente en huesos largos y con mucho menor frecuencia en la columna vertebral, donde puede provocar inestabilidad y compresión de la médula espinal. Es posible confundirla con otras neoplasias, por lo que el diagnóstico definitivo mediante biopsia es imprescindible a fin de establecer el plan terapéutico adecuado, que elimine el riesgo de recurrencia o secuelas neurológicas asociadas, y lograr la estabilidad adecuada de los segmentos vertebrales afectados.

The aneurysmal bone cyst (ABC) is a fast-growing tumor of undefined neoplastic nature. It is occasionally an aggressive benign lesion whose treatment of choice is a complete resection, even though the risk of profuse transoperative bleeding exists. We present a female patient with thoracic spine deformity, with progressive paresthesias and muscle weakness of lower extremities that evolved to paralysis of both lower extremities and sphincter incontinence. Based on radiographic films, lytic lesions were identified at T7 to T9 vertebrae as well as medullary space invasion. In electrophysiologic tests, a complete somatosensorial pathway block was reported. Prior to resection of the neoplastic lesion and thoracolumbar stabilization, an incisional biopsy was performed. There was no postoperative medullary functional improvement. Morphological findings corresponded to an aneurysmal bone cyst at T8. This lesion is mainly located in the long bones and less frequently of the spine, where instability and medullary compression may occur. It is possible to confuse this neoplasia with other lesions. Hence, definite diagnosis with biopsy is necessary for determining an adequate therapeutic plan to eradicate recurrence risk or associated neurologic sequelae, as well as to gain proper stability at the involved vertebral segments.

The feasibility of forecasting influenza epidemics in Cuba

A large influenza epidemic took place in Havana during the winter of 1988. The epidemiologic surveillance unit of the Pedro Kouri Institute of Tropical Medicine detected the begining of the epidemic wave. The Rvachev-Baroyan mathematical model of the geographic spread of an epidemic was used to forecast this epidemic under routine conditions of the public health system. The expected number of individuals who would attend outpatient services, because of influenza-like illness, was calculated and communicated to the health authorities within enough time to permit the introduction of available control measures. The approximate date of the epidemic peak, the daily expected number of individuals attending medical services, and the approximate time of the end of the epidemic wave were estimated. The prediction error was 12%. The model was sufficienty accurate to warrant its use as a pratical forecasting tool in the Cuban public health system

Forecast of acute respiratory infections: expected nonepidemic mobidity in Cuba

A forecast of nonepidemic morbidity due to acute respiratory infections were carry out by using time series analysis. The data consisted of the weekly reports of medical patient consultation from ambulatory facilities from the whole country. A version of regression model was fitted to the data. Using this approach, we were able to detect the starting data of the epidemic under routine surveillance conditions for various age groups. It will be necessary to improve the data reporting system in order to introduce these procedures at the local health center level, as well as on the provincial level

Utilización de modelos matemáticos para la organización de los servicios de atención médica de urgencia en Cuba / Use of mathematical models for the organization of emergency medical care in Cuba

Se exponen modelos matemáticos de aplicación en la República de Cuba para la planificación de camas de hospitalización y de estaciones de ambulancias, en la organización del servicio de atención médica de urgencia en un territorio dado

Sistema de estadísticas sanitarias del policlínico / Sanitary statistical system of the polyclinics

Este trabajo está enmarcado dentro de los estudios que realiza el Ministerio de Salud Pública para la automatización de la información estadística como parte del Sistema Automatizado de Dirección para la Salud Pública. El sistema tiene como objetivo el control y procesamiento de la información estadística relativa a los servicios de consultas médicas y atención a enfermos dispensarizados. Por su diseño, este sistema puede ser aplicado a cualquier policlínico del país que cuente con una microcomputadora SANYO MBC-555 o MBC-885, con Floppy Disk de 5». Esta será operada por una auxiliar de estadística del policlínico, que a través de un diálogo muy interactivo introduce los datos de entrada, los cuales son validados automáticamente y permite la corrección de forma inmediata. A partir de estos datos se obtienen informes sobre las actividades desarrolladas por la unidad asistencial en los períodos que se soliciten, de acuerdo con las necesidades de la dirección del centro y de los niveles superiores del Sistema Nacional de Salud