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Biomedical subjects

K V Toyka

Publications and source records attributed to K V Toyka.

At least 37 records · Page 2Linked to original sources
PubMed2003

Neuropathology and binding studies in anti-amphiphysin-associated stiff-person syndrome.

The authors report a 71-year-old woman with amphiphysin-associated paraneoplastic stiff-person syndrome, opsoclonus, and encephalopathy. The patient's symptoms temporarily responded to plasmapheresis in parallel with a decline of serum anti-amphiphysin antibody titers. Later, the encephalopathy progressed rapidly and the patient died. Binding studies and the detection of autoantibodies in the patient's CNS as well as the treatment response suggest a pathogenic role of the anti-amphiphysin antibodies.

Aged↗
PubMed2003

Creatine monohydrate in DM2/PROMM: a double-blind placebo-controlled clinical study. Proximal myotonic myopathy.

The efficacy and safety of creatine monohydrate (Cr) in patients with myotonic dystrophy type 2/proximal myotonic myopathy were studied in a small placebo-controlled double-blind trial. Twenty patients received either Cr or placebo for 3 months. After 3 months, there were no significant differences of muscle strength as assessed by hand-held dynamometry, testing of maximum grip strength, Medical Research Council scoring, and the Neuromuscular Symptom Score between the two groups. Some measures indicated trends toward mild improvement with Cr. Myalgia improved in two patients.

Adult↗
PubMed2003

Modulation of cytokine mRNA expression by brain-derived neurotrophic factor and nerve growth factor in human immune cells.

Brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) exert various effects on immune cells. Here we studied, whether they influence the cytokine expression pattern in peripheral blood mononuclear cells (PBMCs) or antigen specific T-cells. In PBMCs BDNF and NGF had interindividually variable effects on T helper cell type (Th)1- and Th2-cytokines. However, there was a high correlation between the modulating properties of these neurotrophins (r=0.97) concerning the expression of interleukin (IL) 4, transforming growth factor-beta and tumour necrosis factor-alpha mRNA at a concentration of 100 ng/ml. In myelin basic protein-specific T-cell lines BDNF and NGF increased interferon -gamma mRNA to a moderate extent, but not IL4. No major effects were detected at the cytokine protein level. In conclusion, our results suggest a partial effect of neurotrophins on immune cells, which may be modified by other signals.

Brain-Derived Neurotrophic Factor↗
PubMed2003

IgG from patients with Guillain-Barré syndrome interact with nicotinic acetylcholine receptor channels.

In Guillain-Barré syndrome (GBS), immunoglobulin G (IgG) antibodies block neuromuscular transmission pre- and postsynaptically and thus are of potential pathogenic relevance. We investigated whether IgG from GBS patients has a direct interaction with nicotinic acetylcholine receptor (nAChR) channels. Purified IgG fractions from six GBS patients that blocked neuromuscular transmission in a previous study were analyzed by the patch-clamp technique in combination with an ultrafast system for solution exchange. Sera from three patients with other inflammatory neurological disorders were used as controls. Mouse myotubes expressing native embryonic-type nAChR channels and human embryonic kidney (HEK) 293 cells transiently transfected with recombinant adult-type nAChR channels were used. Repeated 20-ms pulses of acetylcholine (ACh) were applied to outside-out patches in the presence of GBS-IgG. IgG of the patients had a significant reversible blocking action on embryonic- and adult-type nAChR channels with some variability in the magnitude of the block. Activation and desensitization kinetics were not affected when GBS-IgG was applied. None of the control sera blocked the AChR channels. The observed postsynaptic block effect fulfills the criteria of a channel-blocking IgG antibody similar to those seen in autoimmune myasthenia and may contribute to muscle weakness during the acute phase of GBS.

Animals↗
PubMed2003

Preserved myelin integrity and reduced axonopathy in connexin32-deficient mice lacking the recombination activating gene-1.

Mice heterozygously deficient for myelin protein zero (P0) mimicking human Charcot-Marie-Tooth (CMT) disease 1B show T-lymphocyte and macrophage upregulation in peripheral nerves, which aggravates and modulates the genetically mediated demyelinating neuropathy. In connexin32 (cx32)-deficient (cx32(def)) mice, which mimic the X-linked dominant form of CMT (CMTX), T-lymphocyte and macrophage numbers are also significantly elevated in peripheral nerves. To test the hypothesis that immune cells are indeed pathogenic in this model, we cross-bred cx32(def) mice with recombination activating gene-1 (RAG-1)-deficient mice, which lack mature T- and B-lymphocytes. In these immunoincompetent double mutants, the number of endoneurial macrophages was reduced. Furthermore, features indicative of myelin degeneration and axonopathic changes were mitigated in the RAG-1-deficient double mutants, whereas enlarged periaxonal Schwann cell collars, a hallmark specific for cx32-mutants, were not reduced. Since both cx32- and P0 deficiency lead to similar immunopathogenic processes, we conclude that immune-mediated demyelination may be a feature common to many CMT-like neuropathies independent of the genetic origin.

Animals↗
PubMed2002

Serial analysis of cytokine mRNA profiles in whole blood samples from patients with early multiple sclerosis.

In this pilot study, we serially determined the cytokine messenger RNA (mRNA) expression pattern in whole blood samples from 12 patients with clinical isolated syndrome suggestive of early multiple sclerosis (MS) using a new sensitive quantitative polymerase chain reaction (PCR) method. Significantly higher levels of tumor necrosis factor-alpha (TNF-alpha; x 5.1), interferon-gamma (IFN-gamma; x 4.8) and interleukin-10 (IL-10; x 5.6) mRNA were detected in MS patients at the time of a relapse compared to healthy controls. Treatment with i.v. methylprednisolone (MP) led to an increase of IL-4 mRNA and a significant decrease of IFN-gamma and TNF-alpha mRNA expression. In this cohort of clinically stable patients, proinflammatory cytokines remained low during the 1-year follow-up period. As several indications point to a cytokine dysregulation in MS, quantitative analysis of cytokine mRNA profiles in whole blood samples by real time PCR may be a useful immunological marker to monitor disease activity in future therapeutic trials in MS.

Adult↗
PubMed2002

Human cerebral endothelial cells are a potential source for bioactive BDNF.

Inflammatory stimuli within the central nervous system may not only induce tissue damage but may also convey neuroprotection. It has been shown that brain derived neurotrophic factor (BDNF) is a neuroprotective candidate. Here we show that BDNF is constitutively expressed in cultured human cerebral endothelial cells (HCEC) and can further be upregulated under proinflammatory conditions. TNF-alpha treatment resulted in an increase in BDNF mRNA expression and protein levels were significantly elevated after 72 h (69+/-33%, P<0.01). Using functional assays it was demonstrated that BDNF produced by HCEC is bioactive and supports motoneuron survival. In contrast, BDNF expression was reduced by TNF-alpha in human umbilical vein endothelial cells (HUVEC). We conclude that HCEC likely to contribute to neuronal survival under physiological and inflammatory conditions.

Brain-Derived Neurotrophic Factor↗
PubMed2002

Mycophenolate mofetil in the therapy of polymyositis associated with a polyautoimmune syndrome.

Mycophenolate mofetil 1.5 g daily (30 mg/kg body weight) was given to a patient with ankylosing spondylitis, ulcerative colitis, and severe refractory polymyositis after conventional treatment regimes had failed. No severe side effects occurred. Considerable improvement of clinical symptoms and electromyographic findings were seen within 6 months after the initiation of mycophenolate mofetil, allowing for tapering and discontinuation of methylprednisolone. Mycophenolate mofetil may be considered as an useful alternative in the treatment of polymyositis when standard therapeutic regimens fail.

Anti-Inflammatory Agents↗
PubMed2002

Disease progression in amyotrophic lateral sclerosis: predictors of survival.

Predicting the rate of disease progression has become important as trials of new medical treatments for amyotrophic lateral sclerosis (ALS) are planned. Bulbar onset, early impairment of forced vital capacity, and older age have all been associated with shorter survival. We performed a retrospective study to compare survival factors with disease progression in a German ALS population. We analyzed disease progression in 155 patients at intervals of 4 months over a period of 3 years. To evaluate disease progression, the ALS functional rating scale (ALS-FRS), forced vital capacity (FVC%), and a Medical Research Council (MRC) compound score based on a nine-step modified MRC scale were used. We compared age (< 55 years vs. > or =55 years), different sites of disease onset (bulbar vs. limb), and gender to the rate of disease progression and performed survival analyses. No overall significant difference could be detected when analyzing these subgroups with regard to disease progression. By contrast, significantly longer survival was observed in the younger age group (56 months vs. 38 months, P < 0.0001) and in patients with limb-onset disease (51 months vs. 37 months, P = 0.0002). Using Cox analyses values we found that the declines of ALS-FRS, FVC%, and MRC compound score were predictive of survival (P < 0.0001, P = 0.002, and P = 0.003, respectively). Future studies are needed to clarify whether nonspecific factors including muscle atrophy, dysphagia, and coexisting diseases influence prediction of survival in ALS patients. A more precise set of predictors may help to better stratify patient subgroups for future treatment trials.

Age of Onset↗
PubMed2002

[Immunomodulatory staged therapy of multiple sclerosis. New aspects and practical applications, March 2002].

This update of the consensus on escalating immunotherapy in multiple sclerosis includes for the first time also important aspects of diagnosis, documentation, and cost of disease. The application of evidence-based therapeutic recommendations as described in the first two publications of the MSTKG has already improved the treatment situation for MS patients. It appears that the positive attitude towards a more active immunomodulatory therapy also helped to improve MS therapy in general. Due to the increasing use of standardized clinical documentation, individual recommendations for the application of innovative products are now clearer for patients as well as health care providers. The study on the cost of MS performed in several European countries demonstrated that medical treatment constitutes only a small part of the total cost of MS. It was demonstrated that MS-related costs correlate almost exponentially with increasing disability. Therefore, pharmacoeconomic reasons might also speak for early, individually adjusted, and escalating immunotherapy. This would also include a stringent therapy of individual relapses aimed at a complete resolution of clinical symptoms. Recent studies focus on a possible dose-effect relation for recombinant beta-interferons. The available data suggest a possible relation, but they have to be interpreted with caution, as important issues in the design of the studies (e.g., maintenance of blinding) were not adequately addressed. Up to now, there has been no general recommendation for a differential indication of the individual licensed substances, but the different available dose regimes and modes of application allow for an individual adjustment of therapy. In addition to immunomodulatory treatment, vaccinations and their effect on the disease course are important aspects in patient care. According to recent large epidemiological studies, the recommendations have changed as the relevant immunizations with split vaccines (e.g., influenza, tetanus) are now regarded as safe and without increased risk of relapse or disease progression.

Adjuvants, Immunologic↗
PubMed2002

Quantitative analysis of energy metabolism in human muscle using SLOOP 31P-MR-spectroscopy.

OBJECTIVE: Energy metabolism is vital for regular muscle function. In humans, in-vivo analysis using (31)P-MR-spectroscopy (MRS) is mostly restricted to semiquantitative parameters due to technical demands. We applied Spatial Localization with Optimal Pointspread Function (SLOOP) for quantification in human skeletal and cardiac muscle. SUBJECTS/METHODS: 10 healthy volunteers and 4 patients with myotonic dystrophy type 1 were examined using a 1.5 T system (Magnetom VISION) and chemical shift imaging (CSI) for data collection. Concentrations of PCr, ATP and Pi as well as PCr/ATP ratios were calculated by SLOOP. RESULTS: Concentrations of PCr, ATP and Pi were 29.9 +/- 3.4, 7.1 +/- 0.9 and 5.7 +/- 1.2 [mmol/kg] in normal skeletal muscle, corresponding to previously published studies. Two of the patients with a duration of disease longer than 10 years and a pronounced muscle weakness showed a significant decrease of PCr and ATP in skeletal muscle below 10 and 5 mmol/kg. One of these patients had an additional reduction of PCr in cardiac muscle. CONCLUSIONS: With MRS and SLOOP, a more accurate quantitative assessment of metabolism is now available in skeletal and cardiac muscle. Longitudinal studies of larger patient groups will allow to better describe the metabolic disorder in muscle disease over time. Moreover, these techniques offer a new way to quantify treatment effects in future trials.

Adult↗
PubMed2002

Progressive sudomotor dysfunction in amyotrophic lateral sclerosis.

Autonomic dysregulation is part of the complex degenerative process in amyotrophic lateral sclerosis (ALS). To investigate this, sweating was examined at rest in 39 patients with ALS in comparison with a control group. Sweat was collected over a 30 second period over the thenar and hypothenar eminences and on the sole of the foot, using a commercial device based on vapour pressure gradient. The measurements were repeated after three and six months in 10 patients for longitudinal analysis. In early ALS, patients had significantly higher skin water loss than control subjects over the thenar and the hypothenar eminences. In advanced disease stages, sweating was decreased at all sites compared with controls. A significant decline in sweat secretion of about 40% was found over a six month period. The findings suggest an abnormal sympathetic activity with hyperhidrosis in early ALS and a reduction in sweat production as the disease progresses.

Adult↗
PubMed2002

Psychotic symptoms and emotional distress in patients with Guillain-Barré syndrome.

Psychological disturbances in 49 most severely compromised Guillain-Barré syndrome patients were prospectively studied by a semistructured interview and assessed by repeat psychiatric examination during the patients' stay in the neuro-intensive care unit (ICU). Additional information was obtained from attending physicians, nurses and relatives. Anxiety (82%), acute stress disorder, depressive episodes (67%) and brief reactive psychosis (25%) were observed, with oneiroid psychosis (14%) among the latter. Psychotic episodes were strongly associated (p < 0.001) with severe tetraparesis, artificial ventilation and multiple cranial nerve dysfunction. CSF protein concentration was also correlated with the occurrence of psychotic symptoms. Patients themselves experienced loss of communication to be the most difficult condition to cope with. Fifty-five percent explicitly felt reassured by the environment of the ICU and 90% described contact with relatives to be most helpful. Our data suggest that motor deprivation and loss of communication are the conditions most closely connected with the occurrence of psychotic symptoms. Therapeutically, continuous psychosocial support and psychopharmacological measures may both be valuable tools to ameliorate distress.

Adolescent↗
PubMed2002

Fatigue in multiple sclerosis: a comparison of different rating scales and correlation to clinical parameters.

OBJECTIVES: Fatigue is one of the most common, yet poorly defined, disabling symptoms in patients with multiple sclerosis (MS). To delineate more clearly the frequency and type of fatigue, we first compared four widely used fatigue scales in consecutive MS patients. Secondly, to further clarify the nature of fatigue, we investigated its relation to physical disability, course of the disease, immunotherapy, and depression. PATIENTS AND METHODS: Between February and September 2000, 151 consecutive MS patients entering our outpatient clinic (94 relapsing-remitting, 50 secondary progressive, and 7 primary progressive patients; mean age 29.0 +/- 7.3 years, mean disease duration 9.9 +/- 6.7 years, median EDSS 3.5) filled in a standardized questionnaire induding four fatigue scales--Fatigue Severity Scale (FSS), MS-specific FSS (MFSS), Modified Fatigue Impact Scale (MFIS), and Visual Analogue Scale (VAS). Patients were included in the 'MS-related fatigue group' (MS-F) when they stated in the questionnaire that fatigue: 1) is one of their three most disabling symptoms; 2) occurs daily or on most of the days; and 3) limits their activities at home or at work Patients fulfilling none of these criteria were classified as 'MS-related nonfatigue group' (MS-NF). Depression was measured by Beck's Depression Inventory (BDI). RESULTS: Although all scales showed significant differences between MS-F and MS-NF, correlation between these scales was, at best moderate (correlation coeffcients ranging from 0.06 to 0.56). The most discriminative scales were FSS and MFIS, showing no overlap of the 10th and 90th percentiles for the MS-F and MS-NF groups, with cut-off values of 4.6 and 38, respectively. Depression (BDI > or = 18) was present in 24 of 148 patients who filled in the BDI (16%). FSS was significantly correlated with physical disability (r=0.33, p<0.0001) and BDI (r=0.41, p<0.0001), but not with age, disease duration, clinical activity, and treatment with interferon-beta. In multivariate analysis, however, only BDI independently predicted fatigue. CONCLUSIONS: The association of fatigue and depression suggests that there might be either common underlying mechanisms or interdependence by a cause-and-effect relationship that requires further investigation. The weak correlation within various fatigue scales is best explained by the fact that fatigue is a multidimensional symptom and, therefore, the available tests measure and weight different aspects of fatigue. Our findings underline the necessity for a more exact definition of fatigue and the development of more valid tools if these are to be used to evaluate treatments.

Adult↗
PubMed2002

Cellular immunity in inflammatory autoimmune neuropathies.

Autoimmune demyelinating neuropathies, like Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP), are characterized by local inflammation and demyelination of peripheral nerves. The therapeutic response to plasma exchange and IVIg points to an important role for humoral factors in the pathogenesis of these autoimmune disorders of the peripheral nervous system (PNS). The similarity of the human disease with its animal model disease experimental autoimmune neuritis (EAN), and the activation of T-cell and macrophage derived cytokines all indicate that cellular immunity is also of relevance. Many of the basic principles in autoimmune inflammatory neuropathies have been learned from studies in EAN which can now be linked to the human disorders. This article summarizes current aspects of cellular immunity in autoimmune demyelinating disorders of the PNS. Better understanding of these cellular immunoregulatory mechanisms may help to develop new therapeutic strategies.

Apoptosis↗
PubMed2001

Vaccination, prevention, and treatment of experimental autoimmune neuritis (EAN) by an oligomerized T cell epitope.

Using a polypeptide oligomer harboring 16 repeats of the neuritogenic epitope (aa 58-73) of myelin P2 protein separated by spacers, enhancement of the immune response to the P2 protein, an important neuritogenic autoantigen in experimental autoimmune neuritis (EAN), was attempted. In contrast to a previous study with PLP-16-mer antigen-specific response of T cells was attenuated at all doses examined to a variable degree. Treatment of Lewis rats with the P2-16-mer up to 2 months before immunization with P2(53-78) (vaccination) or after immunization but before appearance of disease (prevention) had a strong tolerizing effect against the induction of EAN on immunization with P2(53-78). Moreover, rats injected with 200 microg of the P2-16-mer i.v. on day 11 after disease induction, at which time the initial signs of disease had appeared, were almost completely protected against progression of clinical disease, whereas animals treated with the same amount of monomeric control peptide developed severe disease (treatment). Similar results were obtained by i.v. treatment of adoptive-transfer EAN with the P2-16-mer. The lack of clinical signs of disease after 16-mer therapy could be correlated with a reduced proliferative response of P2(53-78)-specific lymph node cells. The frequency of apoptotic T cells in sciatic nerve or in lymph node cells, however, was not increased by the 16-mer treatment, suggesting that induction of anergy or other forms of peripheral tolerance may be responsible for the effect. Thus, the oligomerized P2 peptide antigen was highly effective in all three treatment modalities examined in this specific autoreactive T cell-mediated immune response.

Animals↗
PubMed2001

Microglial phagocytosis of apoptotic inflammatory T cells leads to down-regulation of microglial immune activation.

Apoptotic cell death is an established mechanism to terminate an inflammatory response in rodent or human brains. Microglia, as the resident phagocyte, is a strong candidate for the clearance of apoptotic lymphocytes. Apoptosis was induced in cultured autologous thymocytes and in myelin basic protein (MBP)-specific, encephalitogenic T cells from Lewis rats by the addition of 0.1 microg/ml methylprednisolone. The amount of phagocytosis of apoptotic cells was assessed using an in vitro phagocytosis assay. Supernatants were collected to measure microglial cytokine secretion. The state of immune activation in microglia was investigated by a T cell proliferation assay and by flow cytometric analysis of microglial surface expression of immune molecules. Microglia ingested specifically apoptotic cells (apoptotic thymocytes as well as MBP-specific T cells) in contrast to nonapoptotic control cells (p < 0.0001). Subsequent secretion of the proinflammatory cytokines TNF-alpha and IL-12 was significantly decreased, while the secretion of IL-10 and TGF-beta was not affected. Furthermore, ingestion of apoptotic cells led to increased microglial MHC class II expression without concomitant increase in MHC class I, costimulatory molecules, and ICAM expression. The Ag-specific activation of MBP-specific T cells in cocultures with microglia that had ingested apoptotic cells was significantly less than that of identical T cells that interacted with nonphagocytosing microglia. Together with negative results obtained in a trans-well system, this is in support of a cell contact-mediated effect. Microglia might play an important role in the clearance of apoptotic cells. The uptake of apoptotic cells by microglia is tolerogenic and results in a reduced proinflammatory cytokine production and a reduced activation of encephalitogenic T cells. This might help to restrict an autoimmune inflammation and minimize damage in the inflamed brain.

Animals↗