Using an NMR metabolomics approach to investigate the pathogenicity of amyloid-beta and alpha-synuclein.

INTRODUCTION: The pathogenicity at differing points along the aggregation pathway of many fibril-forming proteins associated with neurodegenerative diseases is unclear. Understanding the effect of different aggregation states of these proteins on cellular processes is essential to enhance understanding of diseases and provide future options for diagnosis and therapeutic intervention. OBJECTIVES: To establish a robust method to probe the metabolic changes of neuronal cells and use it to monitor cellular response to challenge with three amyloidogenic proteins associated with neurodegenerative diseases in different aggregation states. METHOD: Neuroblastoma SH-SY5Y cells were employed to design a robust routine system to perform a statistically rigorous NMR metabolomics study into cellular effects of sub-toxic levels of alpha-synuclein, amyloid-beta 40 and amyloid-beta 42 in monomeric, oligomeric and fibrillar conformations. RESULTS: This investigation developed a rigorous model to monitor intracellular metabolic profiles of neuronal cells through combination of existing methods. This model revealed eight key metabolites that are altered when neuroblastoma cells are challenged with proteins in different aggregation states. Metabolic pathways associated with lipid metabolism, neurotransmission and adaptation to oxidative stress and inflammation are the predominant contributors to the cellular variance and intracellular metabolite levels. The observed metabolite changes for monomer and oligomer challenge may represent cellular effort to counteract the pathogenicity of the challenge, whereas fibrillar challenge is indicative of system shutdown. This implies that although markers of stress are more prevalent under oligomeric challenge the fibrillar response suggests a more toxic environment. CONCLUSION: This approach is applicable to any cell type that can be cultured in a laboratory (primary or cell line) as a method of investigating how protein challenge affects signalling pathways, providing additional understanding as to the role of protein aggregation in neurodegenerative disease initiation and progression.

[Our experience with chordoma treatment]. / Nase zkusenosti s lécbou chordomu.

PURPOSE OF THE STUDY: The aim of the study was to evaluate the group of patients operated on for chordoma at our department. We present diagnostic and surgical management options relevant to the localisation of chordoma in the spine, and evaluate the results in terms of post-operative complications, tumour recurrence and patient survival. MATERIAL AND METHODS: Between 1989 and 2002 a total of 20 patients diagnosed with chordoma were treated. There were 15 men and five women with an average age of 53 years. The cervical spine was affected in 20 %, thoracic in 15%, lumbar in 25 % and sacral in 40 % of the patients. All of them suffered from back pain, and nine patients (45 %) had neurological symptoms. The average time from the onset of complaints till disease diagnosis was 7.2 months. RESULTS: The average survival time was 63 months, with eight patients (40 %) surviving for more than five years. Of the patients with chordoma of the mobile spine, 66 % were treated by a combined antero-posterior procedure involving somatectomy, vertebral body replacement and posterior stabilisation; for sacral spine chordoma, a dorsal approach was always used. Of 11 patients (55 %) who required repeat surgery, eight had recurrent tumour and three had wound infection. DISCUSSION: Chordomas are rare, slow-growing tumours usually diagnosed with a delay, particularly when localised in the sacral spi- ne. At present magnetic resonance imaging is the essential diagnostic method allowing us to plan the appropriate surgical management.When the mobile spine is affected, a combined antero-posterior procedure including somatectomy, vertebral body replacement with a graft or implant and posterior stabilisation is used.When the sacral spine is involved, some authors prefer en bloc resection from the posterior approach, others use a combined antero-posterior procedure. Chordomas are known to have a high risk of local recurrence. Post-operative radiotherapy, which makes the disease-free interval longer, is recommendedúúú chemotherapy has no effect. CONCLUSIONS: Chordomas are associated with serious diagnostic and therapeutic problems, with frequent local recurrence. Prognosis is good if early diagnosis is made, and en bloc resection is performed.

[Neurological findings in patients treated surgically for spinal metastatic disease]. / Zhodnocení neurologických nálezu u pacientu operovaných pro metastatické postizení pátere.

PURPOSE OF THE STUDY: We present a group of patients with spinal metastatic disease surgically treated at our department, with an evaluation of their neurological outcomes in relation to the initial disease and the surgical technique used. MATERIAL: Between 1989 and 2007 we operated on 748 patients with spinal tumour. Of these, 380 had metastatic disease. The Frankel classification system was used to assess neurological status. METHODS: Based on the Tomita prognostic score, the metastatic disease was evaluated and appropriate surgical procedure was selected (biopsy, posterolateral decompression, posterolateral decompression with stabilisation, somatectomy, or vertebrectomy/spondylectomy). The neurological findings before and after surgery and at follow-up were assessed. RESULTS: Of the 368 patients evaluated, four were pre-operatively classified as Frankel grade A, 29 as grade B, 99 as grade C, 82 as grade D and 159 patients as grade E. Post-operative outcomes were: Frankel grade A, 6 patients B, 27 C, 78 D, 79 and E, 178 patients. Surgery resulted in neurological deterioration by 3 degrees of the Frankel scale in two patients (0.5%), 2 degrees in three patients (0.8%), and by 1 degree in 17 patients (4.6%). Improvement was recorded: by 1 degree in 57 patients (15.5%), 2 degrees in 10 (2,7%) and 3 degrees in two patients (0.5%). Of 23 patients who underwent biopsy, neurological status improved in one (4.3%) and deteriorated also in one patient (4.3%). Of the 85 patients treated by posterolateral decompression, improvement was recorded in 25 (29.4%) and deterioration in two (2.4%). Of the 73 patients undergoing posterolateral decompression with stabilisation, neurological findings improved in 15 (17.9%) and deteriorated in five (6.0%). In the group of 103 patients treated by vertebrectomy, neurological findings improved in 13 (12.6%) and deteriorated in eight (7.8%). At an average follow-up of 15 months, 208 (55.7%) patients presented themselves of these, improvement in neurological status was recorded in 16 (7.8%) and deterioration in eight (3.9%), as compared with the pre-operative values. DISCUSSION: Any comparison with the literature data is difficult, because both the criteria of indication for surgery and the method of treatment differ considerably. Improvement in neurological status was achieved in 69 patients (18.8%). CONCLUSIONS: Metastatic tumours of the spine present a serious diagnosis, with pain often being the first sign of a malignant disease. The degree of neurological deficit, primary tumour site and the extent of metastatic spinal disease (objectively evaluated on the basis of the Tomita score) should determine whether the patient will be operated on or not and, if so, whether a radical or mere palliative procedure will be used. An important factor is multidisciplinary cooperation of attending physicians both preoperatively and during the post-operative care of cancer patients.

[Surgical options in the treatment of myeloma of the spine]. / Moznosti operacního resení myelomového postizení pátere.

Myeloma of the spine seriously affects the stability of the spine and can lead to compression of nerve structures. Instability of the spine caused by pathological vertebral fracture without compression of the nerve structures can be addressed conservatively using an external orthesis. Surgery is indicated in patients whose survival prognosis is 3-6 months in a situation of existing or imminent spinal collapse or nerve damage. The primary aim of the surgery is to stop the progress, improve or, in ideal cases, prevent damage to the nerves. The surgery renews stability of the spine, and reduces or eliminates the painful symptoms. From a surgical perspective, we distinguish between back, front, and combined procedures. The results are evaluated according to the changes found in the nerve findings based on the Frankel grading system. In our sample of 98 patients with myeloma of the spine who underwent surgery, 37 (38%) showed improved nerve findings, 57 (58%) stayed on the same level, neurologically, and only 4 (4%) showed post-operation deterioration of the nerve findings. Early diagnosis and urgent surgical decompression involving eventual stabilization of the spine can prevent irreversible damage to the nervous system under pressure from the myeloma of the spine.

[Infections in surgery of idiopathic scoliosis]. / Infekce pri operaci idiopatické skoliózy.

PURPOSE OF THE STUDY: In this retrospective study, we evaluated infectious complications in the patients undergoing surgical treatment for idiopathic scolions in order to identify risk factors for postoperative infections. MATERIAL: A total of 786 patients with idiopathic scoliosis were operated on during 24 years. In 754 (96%) cases, we used the posterior approach, involving posterior fusion and internal fixation, and subsequent immobilization in a brace. During that period, we recorded 15 (1.9%) deep wound infections in the area of fusion. Early infections were treated by debridement and lavage, with targeted administration of antibiotics, while instrumentation was kept in place. In late und recurrent infections, instrumentation was always removed. METHODS: We investigated a relationship between the infectious agent and the device used, the length of period between surgery and the onset of infection, the effect of device removal on curve progression, the agent causing infection and the effect of allergy to metal or infectious lesions at other body sites on the outbreak of infection. RESULTS: Early infections (within 6 weeks) were observed in six, late in nine patients. Repeat operations were necessary on average after 487 days. Staphylococcus aureus, the most frequent infectious agent, was isolated from four patients; on four occasions, cultivation was negative. Allergy to nickel was found in four patients. Infection was most often associated with the most frequently used Harrington Instrumentation (six cases, 1.1%). However, in relation to the number of patients treated, infection frequency was highest in TSRH (5.0%) and Isola (4.8%) devices. When Miami Moss fixation or the anterior approach was used, no infection was recorded. In comparison with the non-infected cases, the patients with infectious complications showed the same average values for the curve before and after surgery. At a check up, however, the loss of correction increased to 6 degrees and, after instrumentation removal, to 10 degrees as against 3 degrees in the non-infected patients. Pseudoarthrosis developed in two cases. DISCUSSION: The incidence of deep wound infections in patients who had surgery for idiopathic scoliosis was comparable with the data in the relevant literature. A higher number of infections, particularly late ones, in patients treated with the use of modern instrumentation is probably related to a higher volume of these implants. Early infections are a rare feature and their cause is known (allergy, sepsis). Treatment involves surgical intervention; in early infections, instrumentation is retained but is removed in late infections. CONCLUSIONS: Even though our group included a low number of patients with infections, we can conclude that risk factors for the development of infectious complications associated with surgical treatment of idiopathic scoliosis are as follows: allergy, higher age, large volume of metal used for stabilization and the presence of another infectious lesion.

[Radical surgery in tumors of the thoraco-lumbar spine]. / Radikální operace pri nádorovém onemocnení torakolumbální pátere.

PURPOSE OF THE STUDY: In this retrospective study, the outcomes of anterior and posterior approaches, performed either simultaneously or consecutively, in the radical surgical treatment of tumors of the thoracolumbar spine were compared in terms of surgery duration, intra-operative blood loss, neurological findings and complications. MATERIAL: A total of 547 patients with malignant tumors of the spine were treated between 1981 and 2001. Of these, the thoracolumbar spine was affected in 422 cases. Spondylectomy from the combined anterior and posterior approach with decompression, vertebral body replacement and stabilization was indicated in 117 patients, 69 men and 48 women (59% and 41%, respectively). Etiology included metastases in 63 subjects (54%), primary malignant tumor in 37 (32%), benign tumors in 11 (9%) and tumor-like lesions in six patients (5%). Surgery involving two procedures carried out simultaneously by two teams of surgeons was used in 45 cases (38%) and approaches performed consecutively (in either the anteroposterior or the posteroanterior order) were applied in 72 cases (62%). Both groups were nearly identical in relation to the patients' average age and disease etiology. METHODS: In young patients with a solitary tumor of the thoracolumbar spine whose disease had a good prognosis, radical surgery including complete removal of the vertebra affected, decompression of nervous structures, vertebral body replacement and stabilization with 360 degrees fusion was carried out. The simultaneous and consecutive procedures were compared in terms of operative time, intra-operative blood loss, neurological findings and complications. RESULTS: The approaches carried out simultaneously by two teams reduced the total time of surgery and permitted a better correction of the spine affected. This surgical procedure, however, was more demanding in terms of operative skills and involved increased intraoperative blood losses. In 45 patients treated by this procedure, the average operative time was 244 min and intra-operative blood loss was 3313 ml. In 72 patients undergoing consecutive surgery, the average operative time was 345 min and blood loss was 2500 ml. The neurological finding was generally better or unchanged. Of the patients treated consecutively, four (5.5%) experienced deterioration; of those operated on simultaneously, only one patient (2.2%) got worse. Two patients died in each group (2.8% and 4.4%, respectively). DISCUSSION: In order to provide the optimal therapy, each cancer patient should be considered individually with respect to all basic rules of cancer treatment. In this, the radical approach is nowadays preferred. Some authors, however, use only the posterior approach. At our department, the combined anteroposterior approach under one anesthesia is our method of choice with the exception of a serious intra-operative complication such as large blood loss. In this case, the treatment is completed at a subsequent operation one week later. CONCLUSIONS: We prefer an active and radical approach to the therapy of spinal tumors. The simultaneous surgery resulted in an operative time reduced by about 100 min (29%). The consecutive treatment, on the other hand, produced lower blood losses by 813 ml (24%). Complete surgery under one anesthesia was preferred.

[Instrumentation of idiopathic scolioses by isola and miami-moss systems.]. / Instrumentace idiopatických skolióz systémy Isola a Miami-Moss.

In our University department 135 patients were operated and followed up for minimally 2 years postoperatively. Isola system was used in 92 patients, Miami-Moss in 43 patients. The average curve magnitude was preoperatively in Isola group 61,0 degrees , in Miami-Moss 54,8 degrees . Isola was used exclusively posteriorly, Miami Moss also anteriorly (16 cases). In more severe curves the rib osteotomy of concavity was added (22 patients), most severe curves were released by anterior discectomy with interbody fusion (24 patients). The average postoperative correction was in Isola 55,6 %, in Miami Moss 64,1 %, loss of correction in Isola 2,8 degrees, in Miami Moss 4,3 degrees. No complications were observed in Miami group. A double severe complications in one patient were recorded in Isola group, one transient monoparesis and 5 wound infections.The achieved correction and its loss of both systems were practically not different. Key words: idiopathic scoliosis, surgery, Miami Moss, Isola.