No abstract

Protein deprivation causes a delay in neuronal maturation but postnatal recovery can almost completely restore the normal morphology of myenteric neurons.

Several studies describing the ultrastructure and extracellular matrix (ECM) of intervertebral discs (IVDs) involve animal models and specimens obtained from symptomatic individuals during surgery for degenerative disease or scoliosis, which may not necessarily correlate to changes secondary to normal aging in humans. These changes may also be segment-specific based on different load patterns throughout life. Our objective was to describe the ECM and collagen profile of cervical IVDs in young (G1 - <35 years) and elderly (G2 - >65 years) presumably-asymptomatic individuals. Thirty cervical discs per group were obtained during autopsies of presumably-asymptomatic individuals. IVDs were analyzed with MRI, a morphological grading scale, light microscopy, scanning electron microscopy (SEM) and immunohistochemistry (IHC) for collagen types I, II, III, IV, V, VI, IX and X. Macroscopic degenerative features such as loss of annulus-nucleus distinction and fissures were found in both groups and significantly more severe in G2 as expected. MRI could not detect all morphological changes when compared even with simple morphological inspection. The loose fibrocartilaginous G1 matrix was replaced by a denser ECM in G2 with predominantly cartilaginous characteristics, chondrocyte clusters and absent elastic fibers. SEM demonstrated persistence of an identifiable nucleus and Sharpey-type insertion of cervical annulus fibers even in highly-degenerated G2 specimens. All collagen types were detected in every disc sector except for collagen X, with the largest area stained by collagens II and IV. Collagen detection was significantly decreased in G2: although significant intradiscal differences were rare, changes may occur faster or earlier in the posterior annulus. These results demonstrate an extensive modification of the ECM with maintenance of basic ultrastructural features despite severe macroscopic degeneration. Collagen analysis supports there is not a “pathologic” collagen type and changes are generally similar throughout the disc. Understanding the collagen and ultrastructural substrate of degenerative changes in the human disc is an essential step in planning restorative therapies.

-Background:Primary spinal cord intramedullary tumors are rare and present with insidious symptoms. Previous treatment protocols emphasized biopsy and radiation/chemotherapy but more aggressive protocols have emerged. Objective: To report our experience. Method: Forty-eight patients were diagnosed with primary intramedullary tumors. The cervical cord was involved in 27% and thoracic in 42% of patients. Complete microsurgical removal was attempted whenever possible without added neurological morbidity. Results: Complete resection was obtained in 33 (71%) patients. Neurological function remained stable or improved in 32 patients (66.7%). Ependymoma was the most frequent tumor (66.7%). Conclusion: Neurological outcome is superior in patients with subtle findings; aggressive microsurgical resection should be pursued with acceptable neurological outcomes.KEy words: spinal cord, spastic paraparesis, spinal cord neoplasms, ependymoma; microsurgery. tratamento cirúrgico de tumores intramedulares primários em adultosResumo -Introdução: Tumores intramedulares primários são raros e apresentam-se com sintomas insidiosos. Protocolos de tratamento anteriores enfatizavam biópsia e radio/quimioterapia, mas protocolos mais agressivos têm surgido. Objetivo: relatar nossa experiência. Método: Tumores intramedulares foram diagnosticados em 48 pacientes. o segmento cervical estava envolvido em 27% e torácico em 42% dos pacientes. remoção completa foi tentada quando possível sem aumento da morbidade neurológica. Resultados: ressecção total foi obtida em 33 (71%) pacientes. Função neurológica: permaneceu inalterada/melhorou em 32 (66,7%) pacientes. o tumor mais freqüente foi ependimoma (66,7%). Conclusão: o prognóstico é melhor em pacientes oligossintomáticos; ressecção microcirúrgica agressiva deve ser tentada sempre, com resultados clínicos aceitáveis.PALAVrAs-CHAVE: medula espinhal, paraparesia espástica, neoplasias da medula espinhal, microcirurgia.