Neural crest stem cells protect spinal cord neurons from excitotoxic damage and inhibit glial activation by secretion of brain-derived neurotrophic factor

The acute phase of spinal cord injury is characterized by excitotoxic and inflammatory events that mediate extensive neuronal loss in the gray matter. Neural crest stem cells (NCSCs) can exert neuroprotective and anti-inflammatory effects that may be mediated by soluble factors. We therefore hypothesize that transplantation of NCSCs to acutely injured spinal cord slice cultures (SCSCs) can prevent neuronal loss after excitotoxic injury. NCSCs were applied onto SCSCs previously subjected to N-methyl-d-aspartate (NMDA)-induced injury. Immunohistochemistry and TUNEL staining were used to quantitatively study cell populations and apoptosis. Concentrations of neurotrophic factors were measured by ELISA. Migration and differentiation properties of NCSCs on SCSCs, laminin, or hyaluronic acid hydrogel were separately studied. NCSCs counteracted the loss of NeuN-positive neurons that was otherwise observed after NMDA-induced excitotoxicity, partly by inhibiting neuronal apoptosis. They also reduced activation of both microglial cells and astrocytes. The concentration of brain-derived neurotrophic factor (BDNF) was increased in supernatants from SCSCs cultured with NCSCs compared to SCSCs alone and BDNF alone mimicked the effects of NCSC application on SCSCs. NCSCs migrated superficially across the surface of SCSCs and showed no signs of neuronal or glial differentiation but preserved their expression of SOX2 and Krox20. In conclusion, NCSCs exert neuroprotective, anti-apoptotic and glia-inhibitory effects on excitotoxically injured spinal cord tissue, some of these effects mediated by secretion of BDNF. However, the investigated NCSCs seem not to undergo neuronal or glial differentiation in the short term since markers indicative of an undifferentiated state were expressed during the entire observation period.

Lymphatic complications following an operation on varicose veins by patients with advanced venous insufficience

Lymphatic complications are minor complications after varicose vein surgery. The frequency of lymphatic complications following an operation on varicose veins is very rarely discussed in literature. Patients, method: We investigated their frequency in a prospective study. Results: Between January 2004 and December 2005 in the cases of 3565 varicose vein operations we found 345 or 9.7% lymphatic complications, i.d. 123 cysts (3.4%), 24 fistulas (0.7%), 7 lymphorrhoe (0.2%) and 5 lymphoedema (0.14%). Conclusion: Lymphoedema is the only longlasting complication of the varicose vein surgery.

Coping with multiple sclerosis-the role of social support

OBJECTIVE

The aim of this study was to get insights in mechanisms of coping and social support in multiple sclerosis (MS).

BACKGROUND

Multiple sclerosis is the most common chronic inflammatory disease of the central nervous system in young adults. MS strains the patient through its unpredictable course and increasing disability.

MATERIAL AND METHODS

A cross-sectional study was conducted. Two hundred and forty-three patients with MS were consecutively examined at two neurological hospitals. Besides sociodemographic variables, the level of impairment, depression, social support, and coping behavior was assessed.

RESULTS

Researched patients were on average 44.0 years old (SD=11.6), were diagnosed for 8.2 years (SD=7.1), and had a mean EDSS of 4.0 (SD=2.2). Patients with MS with an EDSS of 3.0-6.0 are using more intensively cognitive or behavioral coping techniques than less (EDSS≤2.5) or stronger impaired patients (EDSS≥6.5). The level of impairment was further correlated with the amount of reported social support.

CONCLUSION

Differences in coping behavior could be observed for different levels of impairment through MS. Patients tackle more intensively and more actively with their disease when trying to adapt to increasing disability with an EDSS range between 3.0 and 6.0. In addition, the coping behavior of patients with MS was connected to social support, especially support by family, friends, or other patients with MS. Results refer to the importance of special trainings to enhance coping abilities of patients with MS.

Evaluation of disability in multiple sclerosis patients: a comparative study of the Functional Independence Measure, the Extended Barthel Index and the Expanded Disability Status Scale

This study was conducted to compare the Extended Barthel Index (EBI) to the Functional Independence Measure (FIM) and the Expanded Disability Status Scale (EDSS) as a measure used to assess changes in a patient's need for help with activities of daily living. One hundred patients with multiple sclerosis were evaluated by the same person upon arrival in a rehabilitation clinic and four weeks later. EBI and FIM both proved to be far more sensitive in detecting changes than the EDSS (29% of patients changed their EBI score, 32% their FIM score, 5% their EDSS score). EBI and FIM showed a very high correlation (Spearman correlation coefficient rs = 0.9705). Both scales correlated somewhat less with the EDSS ( rs = -0.7624, resp. -0.7611). Considering the high correlation and equal sensitivity of EBI and FIM, the study recommends the use of the EBI, since it has a simpler rating system and the elimination of some redundant FIM items increases user-friendliness and compliance.

Revealing the quality of movement: A meta-analysis review to quantify the thresholds to pathological variability during standing and walking

Neuromotor processes are inherently noisy, which results in variability during movement and fluctuations in motor control. Although controversial, low levels of variability are traditionally considered healthy, while increased levels are thought to be pathological. This systematic review and meta-analysis of the literature investigates the thresholds between healthy and pathological task variability. After examining 13,195 publications, 109 studies were included. Results from over 3000 healthy subjects and 2775 patients revealed an overall positive effect size of pathology on variability of 0.59 for walking and 0.80 for sway. For the coefficient of variation of stride time (ST) and sway area (SA), upper thresholds of 2.6% and 265mm(2) discriminated pathological from asymptomatic performance, while 1.1% and 62mm(2) identified the lower thresholds for pathological variability. This window of healthy performance now provides science based evidence for the discrimination of both extremely low and extremely high levels of variability in the identification as well as standardised monitoring of functional status in neurological cases.

Identification of functional parameters for the classification of older female fallers and prediction of 'first-time' fallers

Falls remain a challenge for ageing societies. Strong evidence indicates that a previous fall is the strongest single screening indicator for a subsequent fall and the need for assessing fall risk without accounting for fall history is therefore imperative. Testing in three functional domains (using a total 92 measures) were completed in 84 older women (60-85 years of age), including muscular control, standing balance, and mean and variability of gait. Participants were retrospectively classified as fallers (n = 38) or non-fallers (n = 42) and additionally in a prospective manner to identify first-time fallers (FTFs) (n = 6) within a 12-month follow-up period. Principal component analysis revealed that seven components derived from the 92 functional measures are sufficient to depict the spectrum of functional performance. Inclusion of only three components, related to mean and temporal variability of walking, allowed classification of fallers and non-fallers with a sensitivity and specificity of 74% and 76%, respectively. Furthermore, the results indicate that FTFs show a tendency towards the performance of fallers, even before their first fall occurs. This study suggests that temporal variability and mean spatial parameters of gait are the only functional components among the 92 measures tested that differentiate fallers from non-fallers, and could therefore show efficacy in clinical screening programmes for assessing risk of first-time falling.

Is gait variability reliable? An assessment of spatio-temporal parameters of gait variability during continuous overground walking

The assessment of gait variability has become an important indicator for quantifying motor performance. However, the use of treadmills is known to influence the temporal rhythm of gait, while non-continuous (i.e. stop-start) overground walking alters gait variability, leading to erroneous results. Through establishing the "8-walk", an overground walking protocol that allows the collection of a high number of consecutive gait cycles, the aim of this study was to determine the conditions under which gait variability can be assessed reliably. Twelve healthy subjects performed continuous barefoot walking at their preferred speed in a path shaped as an "8". Kinematic data of the dominant foot was collected while subjects walked along the straight 10 m sections of the 8-walk during sessions on two different days. Mean spatio-temporal parameters of gait and gait variability were computed for 10, 20, 30, 40, 50 and 60 consecutive cycles. All mean parameters of gait showed excellent reliability (ICC: 0.88-0.98) with only 10 cycles included in the analysis. However, the reliability of spatial and temporal parameters of gait variability improved with increasing number of cycles (ICC: 0.60-0.90) but levelled-off after 50 consecutive cycles, revealing an inter-day test-retest variability of ≈ 13%. To reliably assess gait variability and evaluate human motor performance, we propose the collection of at least 50 cycles and the use of an 8-walk protocol, which avoids the limitations of treadmill and non-consecutive walking protocols.

ABC-transporter gene-polymorphisms are potential pharmacogenetic markers for mitoxantrone response in multiple sclerosis

Escalation therapy with mitoxantrone (MX) in highly active multiple sclerosis is limited by partially dose-dependent side-effects. Predictors of therapeutic response may result in individualized risk stratification and MX dosing. ATP-binding cassette-transporters ABCB1 and ABCG2 represent multi-drug resistance mechanisms involved in active cellular MX efflux. Here, we investigated the role of ABC-gene single nucleotide polymorphisms (SNPs) for clinical MX response, corroborated by experimental in vitro and in vivo data. Frequencies of ABCB1 2677G>T, 3435C>T and five ABCG2-SNPs were analysed in 832 multiple sclerosis patients (Germany, Spain) and 264 healthy donors. Using a flow-cytometry-based in vitro assay, MX efflux in leukocytes from individuals with variant alleles in both ABC-genes (designated genotype ABCB1/ABCG2-L(ow), 22.2% of patients) was 37.7% lower than from individuals homozygous for common alleles (ABCB1/ABCG2-H(igh), P < 0.05, 14.8% of patients), resulting in genotype-dependent MX accumulation and cell death. Addition of glucocorticosteroids (GCs) inhibited MX efflux in vitro. ABC-transporters were highly expressed in leukocyte subsets, glial and neuronal cells as well as myocardium, i.e. cells/tissues potentially affected by MX therapy. In vivo significance was further corroborated in experimental autoimmune encephalomyelitis in Abcg2(-/-) animals. Using a MX dose titrated to be ineffective in wild-type animals, disease course and histopathology in Abcg2(-/-) mice were strongly ameliorated. Retrospective clinical analysis in MX monotherapy patients (n = 155) used expanded disability status scale, relapse rate and multiple sclerosis functional composite as major outcome parameters. The clinical response rate [overall 121 of 155 patients (78.1%)] increased significantly with genotypes associated with decreasing ABCB1/ABCG2-function [ABCB1/ABCG2-H 15/24 (62.5%) responders, ABCB1/ABCG2-I(ntermediate) 78/98 (79.6%), ABCB1/ABCG2-L 28/33 (84.8%), exact Cochran-Armitage test P = 0.039]. The odds ratio for response was 1.9 (95% CI 1.0-3.5) with each increase in ABCB1/ABCG2 score (from ABCB1/ABCG2-H to -I-, and -I to -L). In 36 patients with severe cardiac or haematological side effects no statistically relevant difference in genotype frequency was observed. However, one patient with biopsy proven cardiomyopathy only after 24 mg/m2 MX exhibited a rare genotype with variant, partly homozygous alleles in 3 ABC-transporter genes. In conclusion, SNPs in ABC-transporter genes may serve as pharmacogenetic markers associated with clinical response to MX therapy in multiple sclerosis. Combined MX/GC-treatment warrants further investigation.

Malignant tumours as a rare cause of recurrent thrombophlebitis of the great saphenous vein

We present two case reports concerning patients who had to undergone surgical treatment according tp the diagnosis of thrombophlebitis with insufficiency of the greater saphenous vein and putative encapsulated haematoma in the lower left leg area. During the operation we found tumours with urgent suspicion of malignancy. The histological examination revealed the diagnosis of mesenchymal chondrosarcoma and malignant peripheral nerve sheath tumour which are extremely malignant, but very rare neoplasmas with unfavourable prognosis. Conclusion: Since both types of tumours are often located below the knee, phlebotomists and vascular surgeons should take them into account as differential diagnosis.

Intravenous immunoglobulin in primary and secondary chronic progressive multiple sclerosis: a randomized placebo controlled multicentre study

In patients with relapsing-remitting multiple sclerosis (MS), IVIG was shown to reduce the relapse rate and progression of disability. In patients with chronic progressive MS, a beneficial effect of IVIG was not documented in placebo controlled studies. This trial investigated the influence of IVIG in primary (PPMS) and secondary (SPMS) chronic progressive MS. Two-hundred and thirty-one patients stratified for PPMS (n=34) and SPMS (n=197) were randomly assigned to IVIG 0.4 g/kg per month or to placebo for 24 months. Primary endpoints were 1) the time to sustained progression of disease identified as worsening of the expanded disability status scale (EDSS) sustained for 3 months, and 2) the improvement of neurological functions defined by a patient's best EDSS score. Secondary endpoints were the proportion of patients with sustained progression, the relapse rate, the assessment of fine motor skills, visual evoked potentials, contrast sensitivity, depression and quality of life. Analysis of the intention-to-treat (ITT) population of combined PPMS and SPMS patients showed that the mean time to sustained progression was 74 weeks in the IVIG compared with 62 weeks in the placebo group (P=0.0406). When PPMS and SPMS patients were analysed separately, the time to sustained progression was also longer in the IVIG group, but the difference was not significant. There was no IVIG-mediated improvement in neurological functions. In the combined per protocol (PP) treated patients, IVIG treatment prolonged time to sustained progression by 13 weeks (P=0.0396). PPMS patients, but not SPMS patients showed a slight favourable IVIG effect on the best EDSS score. In the combined ITT population there were less patients with sustained progression in the IVIG than in the placebo group (P=0.028). The difference was significant in PPMS (P=0.016), but not in SPMS patients. In the combined PP population, there was a trend for a favorable IVIG effect on the rates of patients with sustained progression. In patients with PPMS, this IVIG effect reached significance (P=0.036). Other secondary endpoints did not show significant differences between treatment groups. Eighteen patients with PPMS and 102 patients with SPMS withdrew from the study for various reasons. Treatment was generally well tolerated. It was concluded that monthly IVIG infusion could delay progression of disease in patients with PPMS, and that there was a trend in favour of IVIG treatment in patients with SPMS.

Costs and quality of life of multiple sclerosis in Germany

This cost-of-illness analysis based on information from 2973 patients with multiple sclerosis (MS) in Germany is part of a Europe-wide study on the costs of MS. The objective was to analyze the costs and quality of life (QOL) related to the level of disease severity. Patients from six centres (office- and hospital-based physicians) and patients enrolled in a database were asked to participate in the survey; 38% answered a mail questionnaire. In addition to details on the disease (type of disease, relapses, level of functional disability), the questionnaire asked for information on all resource consumption, medical, non-medical, work absence, informal care, as well as QOL (measured as utility). The mean age of the cohort was 45 years, and 18% of patients were 65 years of age or older. Forty-seven percent of patients had mild disease (Expanded Disability Status Scale [EDSS] score 0-3), 36% had moderate disease (EDSS score 4-6.5) and 12% had severe disease (EDSS score > or =7). The mean EDSS score in the sample was 3.8 (median 4.0), with a mean utility of 0.62. Costs and utility are highly correlated with disease severity. Workforce participation decreases from 73% in very early disease to less than 10% in the very late stages, leading to a tenfold rise in productivity losses in the late stages of disease. Hospitalisation and ambulatory visits rise by a factor of 5-6 between early and late disease; investments and services increase from basically no cost to euro 2700; and informal care increases by a factor of 27 for patients with an EDSS score of 7 and by a factor of 50 for patients at the very severe end of the EDSS scale (8-9). Hence, total mean costs per patient are determined essentially by the distribution of the severity levels in the sample, increasing from approximately euro 18 500 at an EDSS score of 0-1 to euro 70 500 at an EDSS score of 8-9. The same is true for utility, which decreases from 0.86 to 0.10 as the disease becomes severe. However, the utility loss compared to the general population is high at all levels of the disease, leading to an estimated loss of 0.2 quality-adjusted life-years per patient. Relapses are associated with a cost of approximately euro 3 000 and a utility loss of 0.1 during the quarter in which they occur. Compared with a similar study performed in 1999, resource consumption, with the exception of drugs, is somewhat lower. This is most likely due to a difference in the severity distribution of the two samples and to changes in health-care consumption overall in the country, such as the introduction of diagnosis-related groups (DRGs, Fallpauschalen).

Escalating immunotherapy of multiple sclerosis--new aspects and practical application

Recent clinical studies in multiple sclerosis (MS) provide new data on the treatment of clinically isolated syndromes, on secondary progression, on direct comparison of immunomodulatory treatments and on dosing issues. All these studies have important implications for the optimized care of MS patients. The multiple sclerosis therapy consensus group (MSTCG) critically evaluated the available data and provides recommendations for the application of immunoprophylactic therapies. Initiation of treatment after the first relapse may be indicated if there is clear evidence on MRI for subclinical dissemination of disease. Recent trials show that the efficacy of interferon beta treatment is more likely if patients in the secondary progressive phase of the disease still have superimposed bouts or other indicators of inflammatory disease activity than without having them. There are now data available, which suggest a possible dose-effect relation for recombinant beta-interferons. These studies have to be interpreted with caution, as some potentially important issues in the design of these studies (e. g. maintenance of blinding in the clinical part of the study) were not adequately addressed. A meta-analysis of selected interferon trials has been published challenging the value of recombinant IFN beta in MS. The pitfalls of that report are discussed in the present review as are other issues relevant to treatment including the new definition of MS, the problem of treatment failure and the impact of cost-effectiveness analyses. The MSTCG panel recommends that the new diagnostic criteria proposed by McDonald et al. should be applied if immunoprophylactic treatment is being considered. The use of standardized clinical documentation is now generally proposed to facilitate the systematic evaluation of individual patients over time and to allow retrospective evaluations in different patient cohorts. This in turn may help in formulating recommendations for the application of innovative products to patients and to health care providers. Moreover, in long-term treated patients, secondary treatment failure should be identified by pre-planned follow-up examinations, and other treatment options should then be considered.

Neuronal mechanism of nociceptin-induced modulation of learning and memory: involvement of N-methyl-D-aspartate receptors

Nociceptin (also called orphanin FQ) is an endogenous heptadecapeptide that activates the opioid receptor-like 1 (ORL1) receptor. Nociceptin system not only affects the nociception and locomotor activity, but also regulates learning and memory in rodents. We have previously reported that long-term potentiation and memory of ORL1 receptor knockout mice are enhanced compared with those in wild-type mice. Here, we show the neuronal mechanism of nociceptin-induced modulation of learning and memory. Retention of fear-conditioned contextual memory was significantly enhanced in the ORL1 receptor knockout mice without any changes in cued conditioned freezing. Inversely, in the wild-type mice retention of contextual, but not cued, conditioning freezing behavior was suppressed by exogenous nociceptin when it was administered into the cerebroventricle immediately after the training. ORL1 receptor knockout mice exhibited a hyperfunction of N-methyl-D-aspartate (NMDA) receptor, as evidenced by an increase in [3H]MK-801 binding, NMDA-evoked 45Ca2+ uptake and activation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) activity and its phosphorylation as compared with those in wild-type mice. The NMDA-induced CaMKII activation in the hippocampal slices of wild-type mice was significantly inhibited by exogenous nociceptin via a pertussis toxin-sensitive pathway. However, the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor GluR1 subunit at Ser831 and Ser845, and NMDA receptor subunit NR2B at Thr286 were phosphorylated similarly after NMDA receptor stimulation in both type of mice. The expressions of GluR1 and GluR2 also did not change, but the levels of polysialylated form of neuronal cell adhesion molecule (N-CAM) were reduced in the ORL1 receptor knockout as compared with wild-type mice. These results suggest that nociceptin system negatively modulates learning and memory through the regulation of NMDA receptor function and the expression of N-CAM.

Measurement of ataxic symptoms with a graphic tablet: standard values in controls and validity in Multiple Sclerosis patients

Aim of our study was to find a specific measure for the intensity of upper limb tremor and other ataxic symptoms in Multiple Sclerosis (MS) patients, and to establish standard values and test quality parameters. Three hundred and forty-two consecutive patients with different symptoms in the upper limbs (upper motor neuron symptoms, cerebellar upper limb ataxia, and/or sensory deficits in the upper limbs) and 140 healthy controls took part in the study. All patients and controls had to trace over a 25 cm high figure '8' on a graphic tablet, to tap with the stylus on the tablet and to perform the nine-hole-peg test (9HPT). Patients were additionally examined using clinical standard scales to classify motor dysfunctions of the upper limbs. One hundred and eighty-nine patients and 27 controls were tested twice to investigate the test reliability. Kinematic analysis of the tablet data was performed by kernel estimators, oscillatory activity by spectral analysis. Total power in the 2--10 Hz band was very specific for ataxia versus other motor symptoms. Tapping and 9HPT could well distinguish patients from controls, and patients with predominant motor neuron or cerebellar symptoms from patients with predominant sensory dysfunctions. Mean drawing error did not differ between motor and sensory dysfunctions. The test--retest reliability was similarly high for both spectral analysis and 9HPT.

Blockade of AMPA/kainate receptors can either decrease or increase the survival of cultured neocortical cells depending on the stage of maturation

Neurotoxicity has often been associated with glutamate receptor stimulation and neuroprotection with glutamate receptor blockade. However, the relationship may be much more complex. We dissociated cells from the rat neocortical anlage at an early stage of prenatal development (embryonic day 14). The cells were exposed in vitro to agonists and antagonists of alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate (AMPA)/kainate and N-methyl-D-aspartate (NMDA) receptors and the effects on differentiation and survival have been quantitatively and qualitatively evaluated. NMDA and the non-competitive antagonist (5R,10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]-cyclohepten-5,10-imine hydrogen maleate (MK-801) had the expected effects (the agonist decreasing and the antagonist increasing neuronal survival) when applied at a relatively advanced stage of in vitro maturation, but no significant effect in either direction at earlier stages. Kainate also had an effect on cell survival only at an advanced stage (where it decreased the number of cells). However, this cannot be attributed to the absence of functional AMPA/kainate receptors at earlier stages, since: (1) cells could be loaded with cobalt; and (2) early application of kainate dramatically reduced the number of cobalt-positive cells. Furthermore, exposure at early stages to 6,7-dinitroquinoxaline-2,3-dione (DNQX), or GYKI 53655, (competitive and non-competitive AMPA receptor antagonists, respectively) strongly reduced cell survival. The effects were concentration- and time-dependent with a complex time--curve. The decrease in cell number was maximal after antagonist application from 2 to 5 days in vitro. The effects of DNQX could be cancelled by co-application of kainate. When exposed to an antagonist at later stages of development, the number of surviving cells gradually approached control values and finally became significantly higher. Our results suggest that cells of the developing neocortex (and perhaps newly generated cells in the adult brain) require at different stages of their development, an appropriate level of AMPA/kainate receptor activation.

Synaptic and non-synaptic AMPA receptors permeable to calcium

For a long time, alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate (AMPA) receptors permeable to calcium have been considered to be either non-existent or as "atypical". There is now ample evidence that these receptors exist in numerous regions of the nervous system and in many neuronal as well as non-neuronal cell populations. This evidence has been accumulated by several methods, including electrophysiological recording, calcium imaging and cobalt-loading. Functional AMPA receptors permeable to calcium are already expressed at very early stages of embryonic development, well before the onset of synaptogenesis. They are probably involved in the paracrine signaling necessary for construction of the nervous system before becoming involved in synaptic transmission. In immature cells, cyclothiazide strongly increases the steady-state level of responses not only to AMPA, but also to kainate. Ingestion, during pregnancy, of food or drug substances that can cross the placental barrier and act upon the embryonic receptors may constitute a risk for normal development. In the adult nervous system, synaptic as well as non-synaptic (paracrine) AMPA receptors permeable to calcium are probably widely expressed in both glial and neuronal cells. They may also participate in controlling some aspects related to adult neurogenesis, in particular the migration of newly formed neurons.

Day-to-day variability of maximum walking distance in MS patients can mislead to relevant changes in the Expanded Disability Status Scale (EDSS): average walking speed is a more constant parameter

In this preliminary study we measured maximum walking distance and walking time on four consecutive days in 29 patients with clinically stable multiple sclerosis (MS). Patients were included in the study if they could achieve a maximum unaided walking distance of 100 up to 500 m. Our results showed a certain day-to-day variability of maximum walking distance, in some cases meaning changes up to 1.5 points in the expanded disability status scale (EDSS), which could be misinterpreted as a progression of the disease. Simultaneous measurements of maximum walking time showed a similar variability, unlike the mean walking speed which turned out to be more stable. Our results therefore suggest that scoring of MS patients should not be based on one single measurement of the maximum walking distance. The more reliable parameter appears to be the mean walking speed.

[Interferon beta-1b (Betaferon)therapy in patients with relapsing-remitting multiple sclerosis: findings of a prospective, multi-center study of disease progression]

In a survey of disease course, the efficacy and tolerability of 24-month interferon beta-1b therapy for relapsing remitting multiple sclerosis (RRMS) were evaluated in 410 patients. The investigation aimed at obtaining data from general practice and of possibly unknown, unexpected adverse reactions. In the 241 patients still on therapy, efficacy was rated after 24 months as "good" or "very good" in 75% of cases. After 24 months, 36.9% of the patients had no exacerbation (baseline 0.3%). Annual exacerbation rates dropped from 1.5 before treatment to 0.7 in the second treatment year. In the 2 years before treatment, 66.2% had worsened by at least 0.5 points on the extended disability status scale (EDSS). This proportion was reduced to 41.2% after 2 years of treatment. The safety profile corresponded to results from controlled trials. This postmarketing survey supports data from the published controlled interferon beta-1b studies and confirms the main effects of this therapy under routine conditions in general practice.

AMPA receptor activation leads to neurite retraction in tangentially migrating neurons in the intermediate zone of the embryonic rat neocortex

In rat (König et al. [1998] 28th Annual Meeting of the Society of Neuroscience, Los Angeles. 24:314.6) and mouse (Métin et al. [2000] J. Neurosci. 20:696-708), neurons migrating tangentially in the intermediate zone (IZ) of the neocortical anlage express functional AMPA receptors permeable to calcium. The role of these receptors is as yet unknown. We exposed organotypic cultures of rat telencephalon (embryonic day 15) to AMPA receptor agonists or antagonists, and analyzed the effects of these treatments on cells in the IZ labeled with antibodies against the isoforms a, b and c of microtubule associated protein 2 (MAP2) and the polysialylated neural cell adhesion molecule (PSA-NCAM). The presence of functional AMPA receptors permeable to calcium was checked by cobalt-loading. After exposure to AMPA alone for at least 6 hr, we observed a significant increase in the number of rounded, MAP2 positive cells in the IZ close to the migratory front. When AMPA was combined with cyclothiazide, the increase was already significant after 3 hr. These effects were dose-dependent and could be partially or totally blocked by DNQX or GYKI 53655 respectively, that suggests that they are mediated by AMPA receptors. Paracrine AMPA receptor activation might participate, together with other signals, in guiding the migratory stream, or provide stop signals for migrating cells.

The amino terminus of PKA catalytic subunit--a site for introduction of posttranslational heterogeneities by deamidation: D-Asp2 and D-isoAsp2 containing isozymes

Conserved deamidation of PKA catalytic subunit isozymes Calpha and Cbeta--more than 25% at Asn2 in vivo in both cases--has been shown to yield Asp2- and isoAsp2-containing isozymes (Jedrzejewski PT, Girod A, Tholey A, König N, Thullner S, Kinzel V, Bossemeyer D, 1998, Protein Sci 7:457-469). Isoaspartate formation in proteins in vivo is indicative of succinimide intermediates involved in both the initial deamidation reaction as well as the "repair" of isoAsp to Asp by the action of protein L-isoaspartyl (D-aspartyl) O-methyl transferase (PIMT). L-Succinimide is prone to racemization to D-succinimide, which may hydrolyze to D-isoAsp- and D-Asp-containing diastereomers with, respectively, no and poor substrate character for PIMT. To analyze native PKA catalytic subunit from cardiac muscle for these isomers the N-terminal tryptic peptides (T1) of the enzyme were analyzed following procedures refined specifically with a set of corresponding synthetic peptides. The methods combined high resolution high-performance liquid chromatography and a new mass spectrometric procedure for the discrimination between Asp- and isoAsp-residues in peptides (Lehmann et al., 2000). The results demonstrate the occurrence of D-isoAsp- and D-Asp-containing T1 fragments in addition to the L-isomers. The small amount of the L-isoAsp isomer, representing only part of the D-isoAsp isomer, and the relatively large amounts of the L-Asp and D-Asp isomers argues for an effective action of PIMT present in cardiac tissue.

CSF and serum levels of soluble interleukin-6 receptors (sIL-6R and sgp130), but not of interleukin-6 are altered in multiple sclerosis

Interleukin-6 (IL-6) has recently been implicated in multiple sclerosis (MS), since IL-6 deficient mice were resistant to a demyelinating form of experimental autoimmune encephalomyelitis and IL-6 expression was upregulated in MS. The cytokine IL-6 and its action mediating soluble receptors (sIL-6R and sgp130) were measured in cerebrospinal fluid (CSF) and serum of 61 MS patients and 39 controls. In the presence of unchanged IL-6 concentrations, sIL-6R and sgp130 serum levels were significantly increased in MS and correlated with disease severity. Furthermore, sgp130 CSF levels were decreased in MS, suggesting a possibly altered IL-6 regulation in the CSF.

Embryonic raphe neurons grafted in vitro on fetal spinal cord slices recognize specific target areas

To investigate the characteristics of neurotropic signaling involved in specific target recognition by grafted embryonic serotonergic cells, we have developed an in vitro grafting model. Specific raphe nuclei (B1/B2 and B3) were respectively dissected from 14-day-old rat embryos, and partially dissociated cells were cocultured on spinal cord slices from 20-day-old fetuses. After serotonin immunodetection, neurite growth patterns were analyzed by standard photonic or confocal scanning microscopy. Computer reconstruction (maximal signal projection) was used to track individual neurites in spite of their changing depth levels. Whereas the direction and branching of the initial neurite segments did not seem to be significantly influenced by any specific environment, specific growth patterns were developed at some distance from the cell bodies, indicating that neurites are able to recognize their specific targets.

AMPA/kainate receptors permeable to divalent cations in amphibian central nervous system

Glutamate receptors have been studied extensively in mammals but less explored in lower vertebrates. These receptors are present in amphibians. Using a recent method based upon agonist-induced cobalt uptake, we were able to detect the presence of functional alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate receptors permeable to divalent cations in tadpoles and in adults. The uptake specificity was checked by co-application of an antagonist. We studied the distribution of receptor-bearing cells in the principal brain regions. The distribution was similar in the two species studied: Rana esculenta (green frog) and Bufo bufo (common toad). The high number of cobalt-positive cells suggests that the AMPA/kainate receptors permeable to divalent cations play an important role in the anuran nervous system.

[Local ice application in therapy of kinetic limb ataxia. Clinical assessment of positive treatment effects in patients with multiple sclerosis]

Upper limb ataxia is one of the most disabling symptoms of patients with multiple sclerosis (MS). There are some clinically tested therapeutic strategies, especially with regard to cerebellar tremor. But most of the methods used for treatment of limb ataxia in physiotherapy and occupational therapy are not systematically evaluated, e.g. the effect of local ice applications, as reported by MS patients and therapists, respectively. We investigated 21 MS patients before and in several steps 1 up to 45 min after cooling the most affected forearm. We used a series of 6 tests, including parts of neurological status and activities of daily living as well. At each step skin temperature and nerve conduction velocity were recorded. All tests were documented by video for later offline analysis. Standardized evaluation was done by the investigators and separately by an independent second team, both of them using numeric scales for quality of performance. After local cooling all patients showed a positive effect, especially a reduction of intentional tremor. In most cases this effect lasted 45 min, in some patients even longer. We presume that a decrease in the proprioceptive afferent inflow-induced by cooling-may be the probable cause of this reduction of cerebellar tremor. Patients can use ice applications as a method of treating themselves when a short-time reduction of intention tremor is required, e.g. for typing, signing or self-catheterization.

Quality of life in multiple sclerosis in France, Germany, and the United Kingdom. Cost of Multiple Sclerosis Study Group

OBJECTIVE

To assess the quality of life (QoL) of patients with multiple sclerosis in France, Germany, and the United Kingdom with a cross sectional study.

METHODS

Patients were classified into three severity groups according to the expanded disability severity scale (EDSS); stage I, II, and III, corresponding to mild (EDSS 1.0-3.5), moderate (EDSS 4.0-6.0), or severe (EDSS 6.5-8.0) multiple sclerosis respectively. Ninety patients with multiple sclerosis and 30 control patients without multiple sclerosis were recruited in each country. Control patients were matched to the patients with multiple sclerosis according to age and sex. Quality of life was assessed using the functional status questionnaire (FSQ).

RESULTS

The aspects of QoL that were mostly affected in the three countries under study were physical function and general wellbeing. Social role function decreased with increased severity of disease in France and in particular in Germany. Multiple sclerosis did not seem to have an impact on psychological function. The QoL of control patients was systematically higher than that of patients with multiple sclerosis.

CONCLUSIONS

Use of such a generic scale showed that progression of multiple sclerosis is accompanied by a decrease in QoL and suggested that this could be a relevant measurement in assessing the effect of treatment and progression of disease. Variation between countries, however, may be important.

Economic evaluation of multiple sclerosis in the UK, Germany and France

A cross-sectional cost-of-care study was performed to assess the economic burden of multiple sclerosis (MS) in France, Germany and the UK. Patients were stratified into 3 groups according to the Expanded Disability Severity Scale (EDSS): stages I, II and III, corresponding to mild (EDSS 1.0 to 3.5), moderate (EDSS 4.0 to 6.0) and severe (EDSS 6.5 to 8.0) MS, respectively. 90 patients with MS and 30 non-MS control patients were recruited in each country. Control patients were matched to the patients with MS on the basis of age and gender. Demographic, clinical and economic data during the 3-month period prior to entry were collected in patient interviews. Total costs included actual expenditures, such as direct medical and non-medical costs, as well as indirect costs. From the societal perspective, the total cost of MS for 3 months was estimated at 1,928 US dollars, 3,941 US dollars and 5,678 US dollars in France, 2,772 US dollars, 2,056 dollars and 5701dollars in Germany, and 5,125 US dollars, 6,751 US dollars and 14, 622 US dollars in the UK, for stage I, II and III patients, respectively. The major medical cost driver in the UK was outpatient consultations, whereas hospitalisations were the major component in Germany and France. The major cost in the UK arose from the dependence of patients with MS on caregivers, which caused high non-medical, societal costs compared with France and Germany. From both the societal and health insurance perspectives in each country, costs for control patients were lower than those for stage I MS patients. MS represents a major financial burden on the individual, the family, health services and society, and these costs increase with MS progression.

Functional AMPA/kainate receptors in human embryonic and foetal central nervous system

Here, functional AMPA/kainate receptors in human embryonic (5.5-7.5 gestational weeks) and foetal (8-10 gestational weeks) central nervous system tissue, shown by the cobalt labeling method, are reported. Specific agonist-induced cobalt incorporation was detected in brainstem and spinal cord cells, even in the youngest embryo studied. T-AMPA or kainate, but also vegetal toxins such as L-BOAA or acromelate, induced accumulation of cobalt. In contrast, no labeling was observed after exposure to KCl or NMDA. Cobalt labeled cells were particularly prominent in motor regions of brainstem and spinal cord. Co-application of the diuretic agent cyclothiazide, a desensitization blocker at AMPA receptors, dramatically increased the number of stained cells, which was particularly obvious in sensory regions, suggesting different receptor properties in motor versus sensory regions. This is the first study providing evidence for functional AMPA/kainate receptors, permeable to divalent cations, in brainstem and spinal cord at an early stage of human central nervous system development. Since many developmental processes are influenced by the modulation of cytosolic calcium, exposure at critical stages of embryogenesis to food or drug substances modifying the activity of AMPA/kainate receptors may alter brain development.

A conserved deamidation site at Asn 2 in the catalytic subunit of mammalian cAMP-dependent protein kinase detected by capillary LC-MS and tandem mass spectrometry

The N-terminal sequence myr-Gly-Asn is conserved among the myristoylated cAPK (protein kinase A) catalytic subunit isozymes Calpha, Cbeta, and Cgamma. By capillary LC-MS and tandem MS, we show that, in approximately one third of the Calpha and Cbeta enzyme populations from cattle, pig, rabbit, and rat striated muscle, Asn 2 is deamidated to Asp 2. This deamidation accounts for the major isoelectric variants of the cAPK C-subunits formerly called CA and CB. Deamidation also includes characteristic isoaspartate isomeric peptides from Calpha and Cbeta. Asn 2 deamidation does not occur during C-subunit preparation and is absent in recombinant myristoylated Calpha (rCalpha) from Escherichia coli. Deamidation appears to be the exclusive pathway for introduction of an acidic residue adjacent to the myristoylated N-terminal glycine, verified by the myristoylation negative phenotype of an rCalpha(Asn 2 Asp) mutant. This is the first report thus far of a naturally occurring myr-Gly-Asp sequence. Asp 2 seems to be required for the well-characterized (auto)phosphorylation of the native enzyme at Ser 10. Our results suggest that the myristoylated N terminus of cAPK is a conserved site for deamidation in vivo. Comparable myr-Gly-Asn sequences are found in several signaling proteins. This may be especially significant in view of the recent knowledge that negative charges close to myristic acid in some proteins contribute to regulating their cellular localization.

AMPA/kainate receptors modulate the survival in vitro of embryonic brainstem cells

This study aimed at analyzing the involvement of (RS)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/kainate (AMPA/kainate) receptors in the survival of cultured rat embryonic brainstem cells, dissociated on embryonic day 14. The cell number was estimated after pharmacological manipulation of the receptors by exposure to agonists or antagonists. The developmental stage at the moment of drug application was critical for cell survival. We observed after 8 days in vitro a much stronger decrease in the number of gamma-enolase-positive cells when the cultures were treated for 3 days with the antagonist 6,7-dinitroquinoxaline-2,3-dione (DNQX) starting on the day of plating than when DNQX was added after 5 days in vitro. Conversely, exposure to the agonists (RS)-2-amino-3-(3-hydroxy-5-tri-fluoromethyl-4-isoxazolyl)-propion ic acid (T-AMPA) or kainate for 3 days significantly reduced cell survival only when the treatment was initiated after 5 days in vitro. Survival of S-100-positive cells was not affected after exposure to either agonists or antagonists. Neither agonist nor antagonist treatment modified cell proliferation, as assessed by 5-bromo-2'-deoxyuridine (BrdU) staining, suggesting that the decrease in the number of gamma-enolase-positive cells is essentially due to cell death. If some of the processes we observed in vitro correspond to analogous events in vivo, then exposure to excitatory amino acid receptor agonists or antagonists at critical stages of embryogenesis may alter the development of the central nervous system.

Characterisation of the major intrinsic protein (MIP) from bovine lens fibre membranes by electron microscopy and hydrodynamics

The major intrinsic protein (MIP) from bovine lens fibre membranes has been purified from unstripped membranes using a single ion-exchange chromatography step (MonoS) in the non-ionic detergent octyl-beta-D-glucopyranoside (OG). SDS-PAGE has confirmed the purity of the preparation and thin-layer chromatographic analysis has shown that the protein is virtually lipid-free. To establish a stable and monodisperse protein sample, we exchanged OG with decyl-beta-D-maltopyranoside (DeM), another non-ionic detergent, by gel-filtration column chromatography. We conclude that the resulting protein/detergent complex is composed of four copies of MIP (a tetramer) and a detergent micelle. This conclusion is based on: (1) measurement of the weight-average molecular mass (Mw,app) of the protein moiety in the protein/detergent complex by sedimentation equilibrium; (2) measurement of the apparent molecular mass of the complexes formed by MIP in OG, in DeM, in dodecyl-beta-D-maltopyranoside (DoM) and in sodium dodecylsulphate (SDS) by gel filtration; (3) measurement of the apparent molecular mass of pure detergent micelles; (4) measurement of the predicted change in the molecular mass of the MIP/DeM complex after partial enzymatic proteolysis; and (5) measurement of the size and shape of the MIP/detergent complex by electron microscopy and single-particle analysis. Therefore, the tetragonal arrangement of MIP observed in both plasma membranes and junctional membranes in lens fibre cells is maintained in solution with non-ionic detergents.

[Acute foot drop paralysis in multiple sclerosis. Peroneal nerve compression as differential diagnosis of acute onset]

We report on ten patients with clinically definite multiple sclerosis (MS) and acute weakness during dorsiflexion of the foot and toes. Assuming an attack, two patients were treated with corticosteroids, but without any effect. Since there were very few clinical hints (hyposensitivity in the area of distribution of n. peronaeus superficialis in one, positive Hoffmann-Tinel signs in two cases) only detailed neurophysiological examinations finally resulted in locating circumscribed lesions of the peroneal nerves (mainly localized at the head of the fibula), which consequently ended up in peripheral paresis of the dorsiflexion muscles. In six cases the peroneal lesion was caused by direct pressure on the nerve (hard crossing of the legs in five patients, pressing the caput fibulae against the wheelchair in one), and in the other three cases by stretching of the nerve due to genu recurvatum. Seven patients forced this posture with the intention of compensating for ataxia of the trunk and/or gait. After a period of avoiding these mechanisms, we saw five patients for follow-up examinations with evident improvements in the clinical and neurophysiological aspects.

The structure of OmpF porin in a tetragonal crystal form

BACKGROUND

OmpF porin is a trimeric integral membrane protein responsible for the passive transport of small hydrophilic molecules, such as nutrients and waste products, across the outer membrane of Escherichia coli. Very few membrane proteins have been crystallized in three dimensions, yet this stable protein can be obtained in several crystal forms. Comparison of the structures of the same membrane protein in two different packing environments is of major interest, because it allows us to explore the integrity of the structure outside the natural membrane environment.

RESULTS

The structure of OmpF porin in a tetragonal crystal form with two trimers per asymmetric unit has been determined at 3.2 A resolution and compared with that obtained previously in a trigonal crystal form. The lattice contacts involve only polar atoms, whereas extensive hydrophobic protein-protein interactions were found in the trigonal lattice. The trimer structure is virtually identical in both.

CONCLUSIONS

Our comparison reveals that the overall structure of OmpF is not influenced by crystal lattice constraints and, thus, presumably bears close resemblance to the in vivo structure. The tetragonal crystal structure has provided the starting model for the phasing of neutron diffraction data obtained from this crystal form, as described in an accompanying article.

[Syringomyelia, a neglected differential diagnosis in multiple sclerosis. 6 cases from a specialty clinic for multiple sclerosis]

During the last 5 years 11 patients with syringomyelia have been found among 4348 patients (0.25%) entering our hospital, which specializes in multiple sclerosis. Six of these 11 patients had been diagnosed earlier as suffering from multiple sclerosis, some of them after a protracted course of neurological illness. In all 6 patients examination of the cerebrospinal fluid was normal, and visual-evoked potentials (VEP) were normal in all but one case, which is described in detail as case 2 in this report. Magnetic resonance imaging (MRI) showed a Chiari malformation in 3 of 6 syringomyelia patients, who came to us under the diagnosis of multiple sclerosis. MRI also showed subcortical white matter lesions in 5 of 6 patients with syringomyelia. In summary, the diagnosis of multiple sclerosis should be reexamined when one of the following signs is present: (1) demonstration of Chiari malformation; (2) cerebrospinal fluid is normal; (3) visual-evoked potentials are normal. These signs may suggest syringomyelia even after years of primary progressive or relapsing remitting development of multiple neurological deficits and MRI visible white matter abnormalities.

AMPA elicits long-lasting, partly hypothermia-sensitive calcium responses in acutely dissociated or cultured embryonic brainstem cells

This study aimed at testing if, and under which conditions, long-lasting cytosolic calcium responses can be induced in dissociated embryonic brain cells exposed to alpha-amino-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptor agonists. Rat brainstem cells (gestation days 13-14; mean crown-rump lengths 8-11 mm) were mechanically dissociated and loaded with the fluorescent calcium marker Fluo-3 after in vitro delays ranging from 20 min to 6 days. The cells were exposed to various concentrations of AMPA, domoic acid or kainic acid. The evoked fluorescence changes, indicating variations of cytosolic calcium, were recorded and analysed either with a video-microscope or a laser cytometer. Even at the earliest stages, non-desensitizing (or partly desensitizing) calcium responses to AMPA were found. In addition, sequential exposure to AMPA followed either by domoic acid, or by AMPA in the presence of aniracetam, revealed the existence of cells bearing predominantly desensitizing receptors. The non-desensitizing as well as desensitizing response components were blocked by 6,7-dinitroquinoxaline-2,3-dione (DNQX). When the experiments were conducted at 24 degrees C, the cytosolic calcium levels generally returned close to pre-stimulus baseline levels after washout. In contrast, when the working temperature was slightly raised (to 27 degrees C), complex secondary calcium rises were observed not only during prolonged stimulation, but also after short agonist application. The calcium modulation might be correlated with some form of cellular "learning" in the embryonic brain. Under particular conditions, where the regulation processes are either switched off by cell programmes or simply overloaded, the cascade of events comprising secondary calcium rises may lead to cell death.

Early functional glutamate receptors in acutely dissociated embryonic raphe cells

We report for the first time, modulation of cytosolic calcium in response to glutamate and specific glutamate receptor agonists in early embryonic rat brain cells (raphe cells taken at gestation days 13 or 14). Metabotropic as well as ionotropic agonists were effective. Cells responding to kainic acid were particularly prominent in caudal raphe. We used very short post-plating delays (2 to 6 h); it may therefore be assumed that functional receptors already exist in the intact embryonic brain by gestation day 13. Since many developmental processes are influenced by cytosolic calcium modulation, glutamate receptors may play a key role in brain development, well before the extensively studied postnatal peak in receptor density.

Fate of B1-B2 and B3 rhombencephalic cells transplanted into the transected spinal cord of adult rats: light and electron microscopic studies

Embryonic cell suspensions (14-day embryos) containing either B3 or B1-B2 serotonergic cell groups were obtained by microdissection of specific rhombencephalic regions and transplanted into the transected spinal cord of adult male Sprague-Dawley rats. After 3 months of survival, the animals were sacrificed and the spinal cords processed for the immunocytochemical detection of serotonin (5-HT). 5-HT-immunoreactive fibers from B1-B2-grafted cells were selectively distributed in the ventral horn and the intermediolateral cell column (IML) where they established conventional synaptic contacts. However, B3 5-HT cells grew and extended their processes into the dorsal horn where in addition we observed scarce synaptic contacts as in the normal spinal cord. These results suggest that the specificity of the 5-HT innervation of the spinal cord by grafted neurons is due, at least partly, to the presence of local mechanisms mediating guidance and cell recognition, possibly operating in conjunction with preexisting substrate pathways.