Spinal Cord Specimens Research Articles

Loss of NeuN immunoreactivity in rat spinal cord neurons during aging

A morphologic study of the impact of aging on neuron marker expression was performed in different segments of the rat spinal cord. Spinal cord specimens from young (5 months), middle-aged (12 months) and senile (32 months) female rats were assessed. We found a complete loss of neuron-specific nuclear protein (NeuN) immunoreactivity in cervical, thoracic and lumbar segments of the senile animals whereas neuron-specific enolase (NSE) immunoreactivity was comparable in young and senile rats. These findings in otherwise morphologically well preserved spinal cord neurons are of interest and reveal that NeuN may not be a reliable marker to identify neurons in the spinal cord of aging rats.

Characteristics of alpha-synucleinopathy in centenarians

To investigate the characteristics of alpha-synucleinopathy in the brains of centenarians, the autopsied brains and spinal cords from 23 cases were studied. Coronal slices were prepared from a section of the cerebral hemisphere, following the guidelines of the Consortium to Establish a Registry for Alzheimer's Disease (AD) (CERAD) and the consensus guidelines for the clinical and pathologic diagnosis of dementia with Lewy bodies (DLB). Spinal cord specimens were prepared at each segment from the third cervical to the third sacral segment. In all cases, we performed standard stainings of hematoxylin-eosin, Klüver-Barrera, and Gallyas-Braak combined with Luxol fast blue/cresyl violet, and alpha-synuclein (AS), phosphorylated tau (AT8) and beta-amyloid protein immunostainings. One-way ANOVA analysis, Chi-square or Fisher exact test were used for statistical analysis. Overall, AS-positive structures were found in 8 (34.8%) of our 23 centenarians, 6 (35.3%) of 17 demented patients, and four (40%) out of ten AD patients. The frequencies of AS lesions in the brains with senile plaque (SP) stage 0-A, B, and C were 27.7, 33, and 50%, respectively. No statistical differences were found among the frequencies of AS lesions in the subgroups of NFT stages I-II, III-IV, and V-VI (P=0.478). Most cases showed a widespread distribution of AS-positive structures except for one patient, in whose brain only the medulla was involved. The distribution pattern of AS-positive lesions was similar to that in Parkinson's disease or DLB, but the pigmented neurons in substantia nigra were relatively well preserved. Our findings indicate that there is a high frequency of alpha-synucleinopathy in centenarians, SP-positive and AS-positive lesions may involve a synergistic interaction.

COX-2, CB2 and P2X7-immunoreactivities are increased in activated microglial cells/macrophages of multiple sclerosis and amyotrophic lateral sclerosis spinal cord

BackgroundWhile multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS) are primarily inflammatory and degenerative disorders respectively, there is increasing evidence for shared cellular mechanisms that may affect disease progression, particularly glial responses. Cyclooxygenase 2 (COX-2) inhibition prolongs survival and cannabinoids ameliorate progression of clinical disease in animal models of ALS and MS respectively, but the mechanism is uncertain. Therefore, three key molecules known to be expressed in activated microglial cells/macrophages, COX-2, CB2 and P2X7, which plays a role in inflammatory cascades, were studied in MS and ALS post-mortem human spinal cord.MethodsFrozen human post mortem spinal cord specimens, controls (n = 12), ALS (n = 9) and MS (n = 19), were available for study by immunocytochemistry and Western blotting, using specific antibodies to COX-2, CB2 and P2X7, and markers of microglial cells/macrophages (CD 68, ferritin). In addition, autoradiography for peripheral benzodiazepine binding sites was performed on some spinal cord sections using [3H] (R)-PK11195, a marker of activated microglial cells/macrophages. Results of immunostaining and Western blotting were quantified by computerized image and optical density analysis respectively.ResultsIn control spinal cord, few small microglial cells/macrophages-like COX-2-immunoreactive cells, mostly bipolar with short processes, were scattered throughout the tissue, whilst MS and ALS specimens had significantly greater density of such cells with longer processes in affected regions, by image analysis. Inflammatory cell marker CD68-immunoreactivity, [3H] (R)-PK11195 autoradiography, and double-staining against ferritin confirmed increased production of COX-2 by activated microglial cells/macrophages. An expected 70-kDa band was seen by Western blotting which was significantly increased in MS spinal cord. There was good correlation between the COX-2 immunostaining and optical density of the COX-2 70-kDa band in the MS group (r = 0.89, P = 0.0011, n = 10). MS and ALS specimens also had significantly greater density of P2X7 and CB2-immunoreactive microglial cells/macrophages in affected regions.ConclusionIt is hypothesized that the known increase of lesion-associated extracellular ATP contributes via P2X7 activation to release IL-1 beta which in turn induces COX-2 and downstream pathogenic mediators. Selective CNS-penetrant COX-2 and P2X7 inhibitors and CB2 specific agonists deserve evaluation in the progression of MS and ALS.

Effects of Cyclosporin A on Neurological Outcome and Serum Biomarkers in the Same Setting of Spinal Cord Ischemia Model

Spinal cord ischemic injury is one of the feared complications during aortic cross-clamping. The aim of this study was to investigate whether cyclosporin A (CsA) has a protective effect on spinal cord during ischemia in a rabbit model. A total of 22 New Zealand white rabbits were studied in three groups. One of the groups served as a sham group (n=7), in which only laparatomy was performed and closed. One group served as a control group (n=7), in which rabbits had their abdominal aortas cross-clamped for 40 min following median laparatomy. The last group was the CsA group (n=8), in which rabbits underwent the same procedure as the control group as well as CsA infusion at 20 mg/(kg . hr) over 60 min starting with aortic cross-clamping and continuing in the first 20 min of reperfusion. Neurological outcome of rabbits was evaluated according to Johnson's scale at postoperative hours 24 and 48 in all groups, and then they were killed. Their spinal cords were harvested, and segments corresponding to L4-L6 were prepared for pathological examination. Serum neuron-specific enolase (NSE) and nitric oxide (NO) levels were measured prior to and following aortic occlusion, and comparisons were made. Physiological data were similar in all groups. Rabbits in the sham group did not have any neurological deficit. However, all rabbits in the control group showed severe neurological deficits, including total paraplegia in five. According to Johnson's scale, neurological status of the rabbits at postoperative hour 48 was better in the CsA group compared to controls (p<0.01). Pathological examination of spinal cord specimens revealed a higher viability index in the CsA group compared to controls (p<0.01). Serum NSE and NO levels were lower in CsA-treated animals compared to controls. Our results demonstrate that CsA, when administered during ischemia and in the early period of reperfusion, may reduce neuronal damage in the spinal cord in a rabbit model of transient spinal cord ischemia.

Collateral nerve fibers in human spinal cord: Visualization with magnetic resonance diffusion tensor imaging

Diffusion tensor magnetic resonance imaging provides structural information about nerve fiber tissue. The first eigenvector of the diffusion tensor is aligned with the nerve fibers, i.e., longitudinally in the spinal cord. The underlying hypothesis of this study is that the presence of collateral nerve fibers running orthogonal to the longitudinal fibers results in an orderly arrangement of the second eigenvectors. Magnetic resonance diffusion tensor scans were performed with line scan diffusion imaging on a clinical MR scanner. Axial sections were scanned in a human cervical spinal cord specimen at 625 μm resolution and the cervical spinal cord of four normal volunteers at 1250 μm resolution. The spinal cord specimen was fixed and stained for later light microscopy of the collateral fiber architecture at 0.53 μm resolution. Diffusion measured by MR was found to be anisotropic for both white and gray matter areas of the spinal cord specimen; the average fractional anisotropy (FA) was 0.63 ± 0.09 (diffusion eigenvalues λ 1 0.38 ± 0.05 μs/mm 2, λ 2 0.14 ± 0.03 μs/mm 2, λ 3 0.10 ± 0.03 μs/mm 2) in white matter and 0.27 ± 0.04 ( λ 1 0.36 ± 0.04 μs/mm 2, λ 2 0.28 ± 0.03 μs/mm 2, λ 3 0.21 ± 0.04 μs/mm 2) in gray matter. The normal-volunteer FA values were similar, i.e., 0.66 ± 0.04 ( λ 1 1.66 ± 0.14 μs/mm 2, λ 2 0.55 ± 0.02 μs/mm 2, λ 3 0.40 ± 0.01 μs/mm 2) in white matter and 0.35 ± 0.03 ( λ 1 1.14 ± 0.07 μs/mm 2, λ 2 0.70 ± 0.03 μs/mm 2, λ 3 0.58 ± 0.02 μs/mm 2) in gray matter. The first eigenvector pointed, as expected, in the longitudinal direction. The second eigenvector directions exhibited a striking arrangement, consistent with the distribution of interconnecting collateral nerve fibers discerned on the histology section. This finding was confirmed for the specimen by quantitative pixel-wise comparison of second eigenvector directions and collateral fiber directions assessed on light microscopy image data. Diffusion tensor MRI can reveal non-invasively and in great detail the intricate fiber architecture of the human spinal cord.

Diffusion Tensor Imaging of the Spinal Cord

The spinal cord is an important part of the nervous system and provides the connection of the brain with the periphery. It consists not only of a large number of longitudinal fibers, but also contains collateral fibers and a central gray matter structure, which are part of autonomous circuits. Magnetic resonance diffusion tensor imaging can reveal this complex fiber architecture in great detail. This report summarizes the normal findings for ADC, diffusion anisotropy, and diffusion eigenvector directions in the spinal cord. Sagittal and axial diffusion-weighted images of the spinal cord were obtained with line scan diffusion imaging (LSDI) in adults, children, infants, and a spinal cord specimen.

Expression of neurotrimin in the normal and injured adult human spinal cord

Neurotrimin (Ntm) is a member of the family of neural cell adhesion molecules. Its expression pattern suggests that Ntm promotes axonal fasciculation, guides nerve fibers to specific targets and stabilizes synapses as it accumulates coincident with synaptogenesis. Strong labeling of Ntm was observed in motor and sensory areas of the postnatal rat cortex. It is not known whether Ntm is present in adult human spinal cord (SC). In the present study, a monoclonal antibody specific for Ntm (1B1), is applied to the first study of the expression of Ntm in normal and injured adult human SC. (1) To investigate the expression pattern of Ntm in adult normal human SC, and (2) to observe the changes of Ntm expression after SC injury and compare the differences between normal and injured adult human SC. Human SC tissue was obtained from necropsies of patients with (n=5) and without (n=4) SC injury. The 1B1 Ntm monoclonal antibody was used for immunohistochemical staining on paraffin embedded sections with an ABC kit. (1) In total, 12 slides were analyzed for each group from both cervical and thoracic levels. Motor neurons and Clarke's neurons and glial-like cells were mild to moderately positive in all uninjured SC specimens. (2) In injured SC, no staining was observed in the injury epicenter between two and three levels proximally and distally, but was detected five levels away. (3) In patients older than 67 years of age, Ntm-positive inclusions were present in the white matter of the SC with or without injury. (4) Some meningeal cells were strongly Ntm-positive, especially in the uninjured human SC. Ntm is expressed by motor and Clarke's neurons and glial cells in uninjured human SC. The downregulation of Ntm in the injured SC suggests that its expression is regulated by afferent input.

Intrathecal activation of the IL-17/IL-8 axis in opticospinal multiple sclerosis

There are two distinct subtypes of multiple sclerosis in Asians, opticospinal (OS-multiple sclerosis) and conventional (C-multiple sclerosis). In OS-multiple sclerosis, selective and severe involvement of the optic nerves and spinal cord is characteristic, though its mechanisms are unknown. The present study aimed to find out possible differences in the cytokine/chemokine profiles in CSF between OS-multiple sclerosis and C-multiple sclerosis and to delineate the relationships between these profiles and neuroimaging and pathological features. Sixteen cytokines/chemokines, namely interleukin (IL)-1beta, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12 (p70), IL-13, IL-17, interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha, granulocyte colony-stimulating factor (G-CSF), monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1beta (MIP-1beta), were measured simultaneously in CSF supernatants from 40 patients with relapsing-remitting multiple sclerosis (20 OS-multiple sclerosis and 20 C-multiple sclerosis) at relapse and 19 control patients with spinocerebellar degeneration (SCD), together with intracellular production of IFN-gamma and IL-4 in CSF CD4+ T cells. In CSF supernatants relative to controls, IL-17, MIP-1beta, IL-1beta and IL-13 were only significantly increased in OS-multiple sclerosis patients, while TNF-alpha was only significantly increased in C-multiple sclerosis patients, using a cut-off level of 1 pg/ml. IL-8 was significantly elevated in both OS-multiple sclerosis and C-multiple sclerosis patients. MCP-1 was significantly decreased in both OS-multiple sclerosis and C-multiple sclerosis patients, while IL-7 was only significantly decreased in C-multiple sclerosis patients. IL-17, IL-8 and IL-5 were significantly higher in OS-multiple sclerosis patients than in C-multiple sclerosis patients. The increases in IL-17 and IL-8 in OS-multiple sclerosis were still significant even after exclusion of the patients undergoing various immunomodulatory therapies. Assays of intracellular cytokine production revealed that both the IFN-gamma+IL-4- T-cell percentage and intracellular IFN-gamma/IL-4 ratio in CSF cells were significantly greater in C-multiple sclerosis patients than in controls. Contrarily, OS-multiple sclerosis patients showed not only a significantly greater percentage of IFN-gamma+IL-4- T cells than controls but also a significantly higher percentage of IFN-gamma-IL-4+ T cells than C-multiple sclerosis patients. Among the cytokines elevated in multiple sclerosis, only IL-8 showed a significant positive correlation with the Expanded Disability Status Scale of Kurtzke score. Both the length of the spinal cord lesions on MRI and the CSF/serum albumin ratio had a significant positive correlation with IL-8 and IL-17 in multiple sclerosis, in which the spinal cord lesions were significantly longer in OS-multiple sclerosis than in C-multiple sclerosis. Three of six spinal cord specimens from autopsied OS-multiple sclerosis cases demonstrated numerous myeloperoxidase-positive neutrophils infiltrating necrotic lesions. These findings strongly suggest that in OS-multiple sclerosis, in addition to the Th1 cell upregulation seen in C-multiple sclerosis, intrathecal activation of the IL-17/IL-8 axis inducing heavy neutrophil infiltration contributes to extensive spinal cord lesion formation.

The spinal cord in multiple sclerosis: relationship of high-spatial-resolution quantitative MR imaging findings to histopathologic results.

To correlate quantitative magnetic resonance (MR) imaging data (ie, relaxation times and magnetization transfer ratios [MTRs]) with histopathologic findings of demyelination and axonal disease in cervical spinal cord specimens from patients with multiple sclerosis (MS) and control subjects. Formaldehyde-fixed cervical spinal cord specimens from 11 patients with MS-three men and eight women (mean age at death, 66 years +/- 11.3 [standard deviation])-and two female control subjects without neurologic disease (83 and 41 years of age at death) were examined at 4.7 T. Relaxation time measurements and MTR mapping were performed. Analyses included the whole cord area and region-of-interest measurements. Histopathologic analyses included semiquantitative myelin and quantitative axonal analysis. Compared with control specimens (P < .001, analysis of variance), specimens from patients with MS had smaller cord areas (mean area, 59.0 mm(2) +/- 12.5 vs 72.7 mm(2) +/- 10.0), significant prolongation of T1 (mean prolongation, 30%) and T2 (mean prolongation, 13%), and decreased MTRs (mean, 10.5%). Within MS specimens, 58% of the white matter area displayed signal intensity abnormalities on intermediate-weighted MR images. The number of axons in normal-appearing white matter in MS specimens was, on average, 46% lower than the number of axons in white matter in control specimens. All quantitative MR parameters correlated well with demyelination; the correlation with T2 relaxation time was the strongest (r = 0.77, Spearman and Kendall nonparametric correlations). By contrast, quantitative MR parameters correlated less well with axonal density; the correlation with T2 relaxation time was the strongest (r = -0.44, Spearman and Kendall nonparametric correlations). Multilevel analysis, corrected for age and MS phenotype, could not result in a model explaining axonal density on the basis of quantitative MR parameters when myelin density was included as a predictor. Changes in quantitative MR imaging parameters in the cervical spinal cord in MS are mainly determined by demyelination and do not reflect axonal disease well.

The Future of Family Medicine: a collaborative project of the family medicine community.

Recognizing fundamental flaws in the fragmented US health care systems and the potential of an integrative, generalist approach, the leadership of 7 national family medicine organizations initiated the Future of Family Medicine (FFM) project in 2002. The goal of the project was to develop a strategy to transform and renew the discipline of family medicine to meet the needs of patients in a changing health care environment. A national research study was conducted by independent research firms. Interviews and focus groups identified key issues for diverse constituencies, including patients, payers, residents, students, family physicians, and other clinicians. Subsequently, interviews were conducted with nationally representative samples of 9 key constituencies. Based in part on these data, 5 task forces addressed key issues to meet the project goal. A Project Leadership Committee synthesized the task force reports into the report presented here. The project identified core values, a New Model of practice, and a process for development, research, education, partnership, and change with great potential to transform the ability of family medicine to improve the health and health care of the nation. The proposed New Model of practice has the following characteristics: a patient-centered team approach; elimination of barriers to access; advanced information systems, including an electronic health record; redesigned, more functional offices; a focus on quality and outcomes; and enhanced practice finance. A unified communications strategy will be developed to promote the New Model of family medicine to multiple audiences. The study concluded that the discipline needs to oversee the training of family physicians who are committed to excellence, steeped in the core values of the discipline, competent to provide family medicine's basket of services within the New Model, and capable of adapting to varying patient needs and changing care technologies. Family medicine education must continue to include training in maternity care, the care of hospitalized patients, community and population health, and culturally effective and proficient care. A comprehensive lifelong learning program for each family physician will support continuous personal, professional, and clinical practice assessment and improvement. Ultimately, systemwide changes will be needed to ensure high-quality health care for all Americans. Such changes include taking steps to ensure that every American has a personal medical home, promoting the use and reporting of quality measures to improve performance and service, advocating that every American have health care coverage for basic services and protection against extraordinary health care costs, advancing research that supports the clinical decision making of family physicians and other primary care clinicians, and developing reimbursement models to sustain family medicine and primary care practices. The leadership of US family medicine organizations is committed to a transformative process. In partnership with others, this process has the potential to integrate health care to improve the health of all Americans.

Tissue xanthine oxidase activity and nitric oxide levels after spinal cord ischemia/reperfusion injury in rabbits: comparison of caffeic acid phenethyl ester (CAPE) and methylprednisolone

AbstractCaffeic acid phenethyl ester exhibits antioxidant properties. This experimental study was designed to determine the effect of CAPE on nitric NO level and XO activity after reperfusion injury of spinal cord. New Zealand white rabbits were undergone aortic occlusion. CAPE, methylprednisolone or saline were injected intraperitoneally before surgical intervention. Animals were subjected to 21 min of crossclamp time. At the end of occlusion time, the clamps were removed and restoration of the blood flow was verified visually. Animals in sham group underwent a surgical procedure similar to the other groups but the aorta was not occluded. Spinal cord specimens were obtained to determine the tissue levels of NO and XO activity.Both XO activity and NO level in ischemia group were significantly higher than those of sham group (p = 0.0005 and 0.0003, respectively). MP and CAPE had no effect on XO activity after reperfusion. These two agents decreased NO levels nearly to that of sham group after reperfusion. There were no differences between MP and CAPE on reducing NO level. These results suggest that rabbits with ischemia‐reperfusion injury in spinal cord have increased cord concentrations of nitrite and nitrate that are indicative of endogenous overproduction of NO. CAPE may be regarded as an agent that protects spinal cord from ischemia‐reperfusion injury.

Comparison of spinal cord gray matter and white matter softness: measurement by pipette aspiration method.

Although the gray matter of the spinal cord has been thought to be softer than the white matter, there is no evidence to support this belief. Because the spinal cord is extremely soft, it has been difficult to measure the mechanical properties of the gray and white matter. The modulis of elasticity of the gray and white matter were measured in situ by using a pipette aspiration method. The spinal cord specimens were excised from Japanese white rabbits. Specimens were cut to display the surfaces of axial, frontal, and sagittal sections. The surfaces of the gray and white matter were aspirated using a 0.8-mm-inner-diameter glass pipette while monitoring with a video microscope, and the deformed length in the pipette was measured on a monitor. In each case the modulus of elasticity was calculated by comparing the relationship between the aspiration pressure and aspirated volume of the specimen with that determined by finite element analysis. The moduli of elasticity of the gray and white matter were 3.4+/-1.4 kPa (mean +/- standard deviation) and 3.4+/-0.9 kPa in the axial section, 3+/-0.3 kPa and 3.5+/-0.5 kPa in the frontal section, and 3.5+/-0.9 kPa and 2.8+/-0.4 kPa in the sagittal section, respectively. No significant difference in modulus of elasticity was shown between the gray and white matter of the spinal in sections made in various directions.

Monitoring of intrathecal oxygen tension during experimental aortic occlusion predicts ultrastructural changes in the spinal cord

Objective: To study the correlation between intrathecal PO2 and ultrastructural changes in the spinal cord during thoracic aortic occlusion in pigs. Material and methods: In 18 pigs, online intrathecal oxygenation was monitored by a multiparameter Paratrend catheter (Biomedical Sensors, High Wycombe, United Kingdom) during 60 minutes' clamping of the proximal and distal descending thoracic aorta. The animals were randomly divided into 2 groups (A and B) depending on the level of distal aortic clamping. Distal aortic perfusion was restored through an aorto-iliac shunt, which also maintained low thoracic segmental perfusion of the spinal cord in group B. Perfusion-fixation technique was used before harvesting the spinal cord specimens, which later were evaluated with light and electron microscopy by an independent observer. Intrathecal parameters were interpreted as normal if PO2 was more than 0.8 kPa and PCO2 was less than 12 kPa, as intermediate ischemia if PO2 was 0.8 or less or PCO2 was more than 12 kPa, and as absolute ischemia if PO2 was 0.8 or less and PCO2 was more than 12 kPa. Results: Among 6 animals with ultrastructural changes of absolute spinal cord ischemia-reperfusion injury, 5 also had absolute ischemia according to variables derived by the Paratrend catheter. The 2 methods were in agreement in 3 of 5 animals with intermediate ischemia-reperfusion changes and in 5 of 6 animals with normal findings. The accuracy of cerebrospinal fluid PO2 and PCO2 to predict electron microscopy–verified intermediate or absolute ischemia-reperfusion injury was 94%. Conclusions: Monitoring of intrathecal PO2 after clamping of the descending aorta correlated with ultrastructural changes in the spinal cord in this pig model. (J Thorac Cardiovasc Surg 2001;121:316-23)

Post-mortem high-resolution MRI of the spinal cord in multiple sclerosis: a correlative study with conventional MRI, histopathology and clinical phenotype.

We used high-resolution MRI to study the post-mortem appearance of spinal cord multiple sclerosis in relation to histopathology and low-resolution images. Fifty-nine 3 cm long formalin-fixed spinal cord specimens from 19 multiple sclerosis patients and three controls were studied. Clinical characteristics of each patient were reviewed. High-field MRI consisted of proton-density weighted spin-echo imaging with an in-plane resolution of 80 microm. Specimens were also imaged at 1.0 T, with 1 mm pixel resolution. After MRI, the specimens were cut at 5 mm intervals and stained for myelin (Luxol fast blue/cresyl violet) and axons (Bodian method). Two observers scored the MRIs for abnormalities and divided them into (i) well-delineated areas of high signal intensity (SI) and (ii) poorly defined areas of mildly increased SI. Abnormalities were scored semiquantitatively, white matter and grey matter separately. In 81 sections the total area of abnormalities per section was measured on both histopathology sections and on matched high-field MRIs. Abnormalities ranged from just a few abnormal areas to complete involvement of the spinal cord specimen. Patients with an aggressive disease course had more abnormalities than patients with a mild or intermediate disease course. Areas of mildly increased SI were seen in all specimens, and were often found around focal high-SI lesions. However, in six patients, areas of mildly increased SI were the predominant finding on the MRIs, correlating with a primary progressive disease course. Histopathologically, high-SI areas correlated with complete demyelination, while mildly increased SI corresponded with partial demyelination. All areas scored as abnormal by the neuropathologist were also found on the MRIs, and sizes measured using both methods correlated well (r = 0.85, P<0.01). On conventional MRIs, abnormalities could be recognized fairly well. However, better differentiation could be made between high-SI and mildly increased SI abnormalities on the 4.7 T images. In conclusion, high-resolution MRI revealed a great range of abnormalities in spinal cord multiple sclerosis, which related to disease course during life. Furthermore, we found very good correlation between the extent of abnormalities shown by histopathology and the SI changes on proton-density MRIs, mainly relating to demyelination revealed histopathologically.

Spinal cord lesions of myelitis with hyperIgEemia and mite antigen specific IgE (atopic myelitis) manifest eosinophilic inflammation

We report the neuropathological findings of spinal cord specimens obtained from two patients who had localized myelitis with hyperIgEemia and mite antigen specific IgE (atopic myelitis). Both cases showed mild spinal cord dysfunction, and the gadolinium-enhanced area of the isolated spinal cord lesion observed on MRI was biopsied, respectively. Neuropathologically, both cases showed many perivascular lymphocyte cuffings associated with disrupted vessels, and the infiltration of eosinophils in the spinal cord lesions. Both myelin and axons were lost in the lesions, which were associated with astrogliosis. These findings suggest that an allergic mechanism may play a role in this condition.

Functional Outcome in Model of Spinal Cord Ischemia: Use of Enoximone

Ten dogs underwent 60 minutes of aortic occlusion; 5 received enoximone 10 μg·kg−1·min−1 and the other 5 served as controls. Distal and proximal aortic pressures were measured during the procedure. Neurological status was assessed after 72 hours. Spinal cord specimens were taken for electron microscopy. During aortic occlusion, cerebrospinal fluid pressure was 17 ± 3 mm Hg in the control group and 14 ± 4 mm Hg in the enoximone group, while distal aortic pressure was 15 ± 4 mm Hg in the control group compared to 47 ± 6 mm Hg in the enoximone group (p &lt; 0.001). Four dogs in the control group suffered paraplegia but there was no paraplegia in the enoximone group (p &lt; 0.01). Electron microscopy scores indicated significantly less ultrastructural damage (p &lt; 0.01) in the enoximone group (2.73 ± 0.79) than in the control group (7.67 ± 0.89). It was concluded that enoximone was effective in reducing the risk of spinal cord injury during aortic crossclamping.

Some aspects of the blood supply to the spinal cord

The investigation of the area of artery anterior spinalis and afferent branches was performed in 76 cadaveric spinal cord specimens. Different types and variations of spinal blood supply were studied. Quantitative characteristics of those different types and variations were given.

Requirements for obtaining unbiased estimates of neuronal numbers in frozen sections

The use of frozen sectioning is a convenient and rapid means of observing the results obtained using fluorescent retrograde tracers. Quantitation of these results using the biased stereological methods currently available can be associated with large errors. A recently developed stereological tool, the optical dissector, provides unbiased and efficient results, however, the requirements for its use in frozen sections has not previously been established. In this study, a comparison was made of neuron numbers, estimated using the optical dissector method, in the motoneuron pool retrogradely labelled from the rat sciatic nerve with either Fast Blue or Tetramethylrhodamine dextran (fluoro-ruby) in methacrylate embedded and frozen spinal cord specimens. Despite over 50% shrinkage in the frozen sections, compared with virtually no shrinkage in the methacrylate sections, no significant difference in labelled motoneuron numbers was observed, provided this shrinkage was taken into account. Correction for section shrinkage is therefore essential in order to use the optical dissector with confidence to count fluorescent labelled neurons in frozen tissue.

CD44 splice variant involvement in the chronic inflammatory disease of the spinal cord: HAM/TSP

Splice variants of CD44 molecule-harboring exon 10 (v6), often called v6 variants (v6v), are shown to confer tumor progressive, metastatic or invasive capacities. Furthermore, CD44 molecule on activated T-cells are shown to be required for infiltration of these cells into the inflammatory site and for accelerated immune response. Human T-cell lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is caused by HTLV-I infection and characterized by spastic paraparesis and urinary disturbance with perivascular HTLV-I-infected and activated CD4+ T-cell infiltration. In order to explore the underlying mechanism causing the disease after HTLV-I infection, we analyzed CD44 variant expression on peripheral blood mononuclear cells (PBMC) and in the spinal cord specimens from patients with HAM/TSP, and compared them with those from other HTLV-I-infected individuals and controls. We found that v6v expression with special direct link of exons 10 (v6) and 14(v10) was highly expressed in PBMC from patients with HAM/TSP and that v6v and CD4 double positive T-cell infiltration into the spinal cord lesion of HAM/TSP. This combination of CD44 splice variant has not been previously reported in the study of chronic inflammatory disorders and may be a marker molecule for T-cells infiltrating into the central nervous system (CNS), especially the spinal cord.

Methionine Adenosyltransferase Activity in Erythrocytes and Spinal Cord of Patients with Sporadic Amyotrophic Lateral Sclerosis

The role of transmethylation mechanisms in the etiology of amyotrophic lateral sclerosis (ALS) is hitherto unexplored. The activity of l-methionine S-adenosyltransferase (MAT), a regulatory enzyme of S-adenosylmethionine biosynthesis, was investigated in erythrocytes of 21 patients with ALS, spinal cord specimens of 7 ALS patients, and matched controls. In ALS patients the activity of MAT in erythrocytes was sex-dependent. In comparison with controls, the male group presented a 33% higher Vmax (P < 0.05) and a 41% decrease in the affinity of MAT for methionine (Km, P < 0.05). The type of ALS onset (limb or bulbar), age, or duration of the disease did not influence erythrocyte MAT activity. In the spinal cord, the activity of MAT was homogeneously distributed through dorsal horn, ventral horn, and white matter. Comparisons between data from controls and ALS patients and analysis of sex effect showed no significant differences. The kinetic difference of erythrocyte MAT in the male group of ALS patients might be interesting to explore since it is well known that there is a male predominance of 1.5 to 2.5:1 in ALS.