Real-life clinical use of natalizumab and fingolimod in Austria.

OBJECTIVES: To compare the efficacy of natalizumab or fingolimod in a nationwide observational cohort using prospectively collected data. MATERIALS AND METHODS: We included all patients starting treatment with natalizumab or fingolimod documented in the Austrian MS Treatment Registry (AMSTR) from 2011 and staying on therapy for at least 24 months. We used propensity scores for several matching methods and as a covariate in multivariate models to correct for the bias of this non-randomized registry study. RESULTS: The study cohort includes 588 patients with RRMS. Ten patients did not produce a propensity score in the common support region, thus leaving 578 cases for final analyses, 332 in the fingolimod and 246 in the natalizumab group. Mean annualized relapse rates (ARR) during the 24 months observation period were 0.19 under fingolimod and 0.12 under natalizumab treatment (P = .005). No statistical significant differences were found analysing the log-transformed ARR, probability for experiencing a relapse, EDSS progression and EDSS regression. The hazard ratio for switching treatment from fingolimod comparing with natalizumab was 0.36 (95% CI: 0.247-0.523), P < .001. CONCLUSIONS: The generalized linear model (GLM) for relapse count as Poisson distributed dependent variable and propensity score as covariate showed a statistically significant reduction for the mean relapse count in the natalizumab group compared with fingolimod. This effect was smaller in the analyses of log-transformed ARR with propensity score matching, loosing statistical significance although showing the same direction for the effect. We assume that the GLM was the more sensitive model analysing this question.

Late age onset of amyotrophic lateral sclerosis is often not considered in elderly people.

INTRODUCTION: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease causing an upper and lower motor neuron loss. It is neurology textbook knowledge that the mean age of onset is about 60 years. However, recent investigations show an increasing incidence in older persons. We therefore evaluated whether ALS is potentially not considered in elderly people with ALS symptoms, respectively, not recognized. MATERIALS AND METHODS: We included retrospectively all patients with ALS diagnoses after work-up that were admitted to our neurological and geriatric departments from 2007 to 2010 and collected their clinical data. The diagnosis of ALS was based on the El Escorial criteria. Patients were grouped into three categories according to age (<50, between 50 and 70, >70), and differences in clinical and/ or biographical factors were investigated. RESULTS: We identified 35 patients (18 men and 17 women) with a median age at onset of 71.5 years (range: 36-87 years). When establishing the diagnosis, 51% were older than 70 years, 40% (14/35) between 50 and 70, and only 9% younger than 50. Only in 46 per cent of patients who were sent to our departments with ALS symptoms ALS was considered by the referring physician. CONCLUSION: Late age onset of ALS seems to be more common than formerly assumed and is presumably under-recognized in elderly patients. ALS needs to be considered as a differential diagnosis in older patients. Potential factors accounting for older people being underdiagnosed with ALS relate to frequent presentation with symptoms like dysphagia, frailty or general weakness for other reasons.

[Surgical Treatment of Calcaneus Fractures with C-Nail]. / Operacní lécení zlomeniny patní kosti pomocí C-hrebu.

PURPOSE OF THE STUDY The calcaneus bone is the largest tarsal bone of a complex shape, the restoration of which after fracturing, often caused by a high-energy injury, is critical. The top priority in treating these fractures is to correctly asses the condition of the surrounding soft tissues that may be further excessively traumatized by inappropriate timing, surgical approach or technique. Even when adhering to all the rules and guidelines, complications in surgical wound healing have been described in up to 16-33% cases when the extended lateral approach was used. Therefore, the development of minimally invasive techniques, approaches and implants are a promise for improvement. One of them is the C-Nail developed by Medin. MATERIAL AND METHODS In the period from 1 January 2014 to 30 March 2017, a total of 25 patients with calcaneus bone fracture treated with C-Nail using the sinus tarsi approach were followed up at our department. Radiological assessment was made in the patients, the fractures were classified by Sanders and Essex-Lopresti classification systems, the Böhler and Gissane angles before and after reduction were measured. The occurrence of postoperative complications in soft tissue healing and complications caused by the C-Nail and the functional outcome according to the Ankle-Hindfoot Score (AOFAS) were tracked. RESULTS Only one complication in wound healing, namely in case of sinus tarsi approach, was reported in this group of patients. In 9 patients, prominence of osteosynthesis material was observed. Of whom in 4 patients a clinically significant prominence into posterior talocalcaneal articulation was present. Severely limited subtalar range of motion was seen in 5 patients, in other three patients ankylosis was observed, or arthrodesis performed. 8 patients experienced mild reduction of subtalar joint range of motion. 6 patients suffered from mild reduction of range of motion in talocrural joint. The functional outcome according to the Ankle-Hindfoot Score (AOFAS) was 89.4 on average. CONCLUSIONS Our so far limited experience with the osteosynthesis of calcaneal fractures using the C-Nail entitles us to claim that this type of osteosynthesis material allows for adequate stability and subsequent healing of a correctly reduced calcaneal fracture. It is an implant inserted by a minimally invasive surgery and the fracture reduction, when mastering the learning curve, can be efficiently performed from sinus tarsi approach. In our group of patients, the number of complications in soft tissue healing was low, which is why we believe that this type of osteosynthesis is another suitable option to treat the comminuted calcaneal fractures. The handling of the implant as such and other osteosynthesis material is safe provided all the rules covered in detail in the discussion are observed. Key words: calcaneal fracture, C-Nail, sinus tarsi approach.

[Influence of the Weather on the Incidence of Fractures in the Elderly]. / Vliv pocasí na výskyt zlomenin ve stárí.

PURPOSE OF THE STUDY The incidence of geriatric fractures (proximal femur, distal radius, proximal humerus and thoracolumbar spine injuries) in the population increases with ageing. However, the role of weather conditions, such as icy and slippery winter, should not be overlooked. A deeper insight into this relationship may bring about a better understanding of the fracture aetiology and thus allow for improvement in the prevention of fractures in elderly people. MATERIAL AND METHODS This prospective study included 676 patients (469 women and 207 men) aged 65 and over. Relationships between the incidence of geriatric fractures in these patients and the season, weather phenomena (i.e., air temperature, atmospheric pressure, air humidity, wind speed, visibility, rain, snow, mist and storm) and global biometeorological data in the period from 1 January 2012 to 31 December 2013 were investigated. Patients with high velocity trauma or those with pathological fractures were excluded. Time (day/night), the place of injury (outdoor/indoor/home environment), comorbidities and chronicuse medication were also recorded. Weather forecast records with weather health loads (biotropic indices) were obtained from the commercial service Weather Underground and the Czech Hydrometeoro-logical Institute. The results were statistically analysed using the Statistika 12 programme. RESULTS The incidence of fractures was higher in winter months but there was no statistically significant correlation between the number of fractures and various weather characteristics (temperature, atmospheric pressure, air humidity, wind speed, visibility, rainfall, snow, mist or storm). On the other hand, a relationship between the incidence of geriatric fractures and the biometeorological data (biotropic index) for that day was significant (r = 0.65, p= 0.0401). The majority of fractures occurred during the daytime (83.7%) and in the indoor environment (83.1%); of the latter fractures, 85.2% were home injuries. The most frequent comorbidities included cardiovascular disease (36.2%), obesity (31.1%) and diabetes mellitus (25.4%). DISCUSSION Studies investigating seasonal patterns in relation to the incidence of geriatric fractures are contradictory. Sixteen previous studies have examined seasonal variations and the incidence of some types of geriatric fractures in different parts of the world. The majority of them have dealt with hip fractures, three with forearm injuries and one compared the incidence of hip, distal forearm, proximal humerus and ankle fractures in the four seasons of the year. Of 13 studies in geographic areas located north of 40°latitude, eight showed no seasonal variation in the incidence of fractures, four recorded an increase in the number of fractures in winter and two showed an increased number of fractures in summer. Three of them also studied the effect of daily temperature. Only one study paid attention to biometeorological data and related the biotropic index to the number of injuries treated at the emergency department. Three studies showed that fractures occurred most frequently in the home environment and during the daytime. CONCLUSIONS This study did not prove any statistically significant relationship between the incidence of geriatric fractures and different weather phenomena. Nevertheless, it showed a higher incidence of fractures in winter, from December to February. Most fractures occurred in indoor environments and during the day. A high value of the biotropic index was significantly related to the incidence of geriatric fractures. The most frequent comorbidities included cardiovascular disease, obesity and diabetes mellitus. Key words: geriatric fracture, season, weather, biometeorological forecast.

High interindividual variability in the CD4/CD8 T cell ratio and natalizumab concentration levels in the cerebrospinal fluid of patients with multiple sclerosis.

Strongly decreased leucocyte counts and a reduced CD4/CD8 T cell ratio in the cerebrospinal fluid (CSF) of natalizumab (NZB)-treated multiple sclerosis (MS) patients may have implications on central nervous (CNS) immune surveillance. With regard to NZB-associated progressive multi-focal leucoencephalopathy, we aimed at delineating a relationship between free NZB, cell-bound NZB, adhesion molecule (AM) expression and the treatment-associated shift in the CSF T cell ratio. Peripheral blood (PB) and CSF T cells from 15 NZB-treated MS patients, and CSF T cells from 10 patients with non-inflammatory neurological diseases and five newly diagnosed MS patients were studied. Intercellular adhesion molecule-1 (ICAM-1), leucocyte function antigen-1 (LFA-1), very late activation antigen-4 (VLA-4), NZB saturation levels, and T cell ratios were analysed by flow cytometry. NZB concentrations were measured by enzyme-linked immunosorbent assay (ELISA). Lower NZB saturation levels (P<0.02) and a higher surface expression of ICAM-1 and LFA-1 (P<0.001) were observed on CSF CD8 T cells. CSF T cell ratios (0.3-2.1) and NZB concentrations (0.01-0.42 µg/ml) showed a pronounced interindividual variance. A correlation between free NZB, cell-bound NZB or AM expression levels and the CSF T cell ratio was not found. Extremely low NZB concentrations and a normalized CSF T cell ratio were observed in one case. The differential NZB saturation and AM expression of CSF CD8 T cells may contribute to their relative enrichment in the CSF. The reduced CSF T cell ratio appeared sensitive to steady-state NZB levels, as normalization occurred quickly. The latter may be important concerning a fast reconstitution of CNS immune surveillance.

Metamorphosis enhances the effects of metal exposure on the mayfly, Centroptilum triangulifer.

The response of larval aquatic insects to stressors such as metals is used to assess the ecological condition of streams worldwide. However, nearly all larval insects metamorphose from aquatic larvae to winged adults, and recent surveys indicate that adults may be a more sensitive indicator of stream metal toxicity than larvae. One hypothesis to explain this pattern is that insects exposed to elevated metal in their larval stages have a reduced ability to successfully complete metamorphosis. To test this hypothesis we exposed late-instar larvae of the mayfly, Centroptilum triangulifer, to an aqueous Zn gradient (32-476 µg/L) in the laboratory. After 6 days of exposure, when metamorphosis began, larval survival was unaffected by zinc. However, Zn reduced wingpad development at concentrations above 139 µg/L. In contrast, emergence of subimagos and imagos tended to decline with any increase in Zn. At Zn concentrations below 105 µg/L (hardness-adjusted aquatic life criterion), survival between the wingpad and subimago stages declined 5-fold across the Zn gradient. These results support the hypothesis that metamorphosis may be a survival bottleneck, particularly in contaminated streams. Thus, death during metamorphosis may be a key mechanism explaining how stream metal contamination can impact terrestrial communities by reducing aquatic insect emergence.

What to expect after natalizumab cessation in a real-life setting.

BACKGROUND: To minimize the risk of progressive multifocal leucoencephalopathy (PML), treatment with natalizumab is often stopped after 2 years, but evidence upon rebound of disease activity is limited and controversial. OBJECTIVE: To evaluate effects of natalizumab discontinuation on clinical disease activity within twelve months after cessation. METHODS: We retrospectively analyzed data of 201 patients with MS who discontinued natalizumab between 2007 and 2012. Mean change scores of annualized relapse rate (ARR) and expanded disability status scale (EDSS) were calculated for detection of rebound disease activity after twelve months. RESULTS: Natalizumab exposure did not exceed 2 years in 50.2% of patients, and the most common reasons for discontinuation were a long treatment period and concern of PML (56%). A total of 11.9% experienced a rebound phenomenon within twelve months. Mean ARR prenatalizumab was lower (P = 0.001, 95% CI -1.0-0.000) and treatment response to natalizumab poorer (P < 0.001, 95% CI 0.4-1.3) in patients with rebound compared to those without, but rebound was not associated with brief exposure to natalizumab (P = 0.159, 95% CI -9.3-1.5). 86.1% of patients switched to another therapy. Patients without rebound were found more often in the group starting an alternative treatment early (P = 0.013). CONCLUSION: Our data suggest that rebound of MS disease activity affects a subgroup of patients (11.9%), especially those with low disease activity before natalizumab therapy and a longer treatment gap after its withdrawal.

Natalizumab saturation: biomarker for individual treatment holiday after natalizumab withdrawal?

BACKGROUND: More and more patients with multiple sclerosis (MS) switch from natalizumab to fingolimod because of the risk of progressive multifocal leukoencephalopathy. The duration of the treatment holiday is still under debate referring to a possible recurrence of disease activity. AIM OF THE STUDY: The aim of this study was to evaluate the prognostic value of natalizumab saturation on T cells for the recurrence of clinical and radiological disease activity. METHODS: Cell surface-bound natalizumab saturation (in%) of CD8+ and CD4+ T cells from five patients with MS was determined before initiation of fingolimod by flow cytometry and related to clinical and MRI outcome during a 6-month follow-up. RESULTS: In two patients with either clinical or radiological disease activity, the natalizumab saturation on CD8+ and CD4+ T cells was <30%. In contrast, the remaining three patients with absence of disease activity had a median natalizumab saturation of 70% (range 59-79%) on CD4+ and 66% (range 52-68%) on CD8+ T cells. CONCLUSIONS: The data of this pilot study indicate that clinical and radiological disease activity is closely linked to natalizumab saturation at the time point of switch. The determination of natalizumab saturation may be an essential tool to monitor cessation of natalizumab treatment.

Glatiramer acetate attenuates the pro-migratory profile of adhesion molecules on various immune cell subsets in multiple sclerosis.

An altered expression pattern of adhesion molecules (AM) on the surface of immune cells is a premise for their extravasation into the central nervous system (CNS) and the formation of acute brain lesions in multiple sclerosis (MS). We evaluated the impact of glatiramer acetate (GA) on cell-bound and soluble AM in the peripheral blood of patients with relapsing-remitting MS (RRMS). Fifteen patients treated de novo with GA were studied on four occasions over a period of 12 months. Surface levels of intracellular cell adhesion molecule (ICAM)-1, ICAM-3, lymphocyte function-associated antigen (LFA)-1 and very late activation antigen (VLA)-4 were assessed in T cells (CD3(+) CD8(+) , CD3(+) CD4(+) ), B cells, natural killer (NK) cells, natural killer T cells (NK T) and monocytes by five-colour flow cytometry. Soluble E-selectin, ICAM-1, ICAM-3, platelet endothelial cell adhesion molecule (PECAM)-1, P-selectin and vascular cell adhesion molecule (VCAM)-1 were determined with a fluorescent bead-based immunoassay. The pro-migratory pattern in RRMS was verified by comparison with healthy controls and was characterized by up-regulation of LFA-1 (CD3(+) CD4(+) T cells, B cells), VLA-4 (CD3(+) CD8(+) T cells, NK cells), ICAM-1 (B cells) and ICAM-3 (NK cells). Effects of GA treatment were most pronounced after 6 months and included attenuated levels of LFA-1 (CD3(+) CD4(+) ) and VLA-4 (CD3(+) CD4(+) , CD3(+) CD8(+) , NK, NK T, monocytes). Further effects included lowering of ICAM-1 and ICAM-3 levels in almost all immune cell subsets. Soluble AM levels in RRMS did not differ from healthy controls and remained unaltered after GA treatment. The deregulated pro-migratory expression profile of cell-bound AM is altered by GA treatment. While this alteration may contribute to the beneficial action of the drug, the protracted development and unselective changes indicate more secondary immune regulatory phenomena related to these effects.

Cerebrospinal fluid parameters of B cell-related activity in patients with active disease during natalizumab therapy.

Recently, the disappearance of oligoclonal bands (OCBs) from the cerebrospinal fluid (CSF) of a few natalizumab-treated patients with multiple sclerosis (MS) has been reported. This is interesting since CSF-restricted OCB are believed to persist in MS. We pooled CSF data from 14 MS centers to obtain an adequate sample size for investigating the suspected changes in central nervous system (CNS)-restricted humoral immune activities in the context of natalizumab therapy. In a retrospective chart analysis, CSF parameters of blood-CSF barrier integrity and intrathecal IgG production from 73 natalizumab-treated MS patients requiring a diagnostic puncture for exclusion of progressive multifocal leukoencephalopathy were compared with CSF data obtained earlier in the course of disease before natalizumab therapy. At the time of repeat lumbar puncture, local IgG production (according to Reibergram) was significantly reduced (p < 0.0001) and OCB had disappeared in 16% of the patients. We therefore conclude that natalizumab therapy interferes with intrathecal antibody production at least in a significant number of patients.

Loop-Mediated Isothermal Amplification and Polymerase Chain Reaction Methods for Specific and Rapid Detection of Rhodococcus fascians.

Rhodococcus fascians is a phytopathogenic actinobacterium which causes leafy galls and other plant distortions that result in economically significant losses to nurseries producing ornamental plants. Traditional assays for detection and identification are time-consuming and laborious. We developed a rapid polymerase chain reaction (PCR) diagnostic assay based on two primer pairs, p450 and fas, which target the fasA and fasD genes, respectively, that are essential for pathogenicity. We also developed a faster, more convenient, loop-mediated isothermal amplification (LAMP) assay targeting the fasR gene, which regulates expression of virulence genes. Both assays were evaluated for sensitivity and specificity in vitro and in planta. The p450 and fas primers amplified DNA only from pure cultures of pathogenic reference isolates of R. fascians. Nonpathogenic isolates and 51 other plant-associated bacteria were not amplified. The PCR primers correctly detected pathogenic R. fascians from 73 of 75 (97%) bacterial strains isolated from naturally infected plants. The PCR assay correctly discriminated between pathogenic R. fascians and other bacteria in 132 of 139 (95%) naturally infected plants, and in 34 of 34 (100%) artificially inoculated plants. The fas primers were slightly more accurate than the p450 primers. The LAMP assay accurately detected pathogenic R. fascians in 26 of 28 (93%) naturally infected plants and did not react with 23 asymptomatic plants. The LAMP primers also amplified product for DNA extracts of 40 of 41 bacterial strains isolated from plants with leafy galls. The detection limit of both the PCR and LAMP assays was approximately 103 CFU/30-µl reaction. These new tools allow fast, reliable, and accurate detection of R. fascians in vitro and in planta. The LAMP assay in particular is a significant advancement in rapid R. fascians diagnostics, and enables those with limited laboratory facilities to confirm the presence of this pathogen in infected plants.

Multigrid methods for isogeometric discretization.

We present (geometric) multigrid methods for isogeometric discretization of scalar second order elliptic problems. The smoothing property of the relaxation method, and the approximation property of the intergrid transfer operators are analyzed. These properties, when used in the framework of classical multigrid theory, imply uniform convergence of two-grid and multigrid methods. Supporting numerical results are provided for the smoothing property, the approximation property, convergence factor and iterations count for V-, W- and F-cycles, and the linear dependence of V-cycle convergence on the smoothing steps. For two dimensions, numerical results include the problems with variable coefficients, simple multi-patch geometry, a quarter annulus, and the dependence of convergence behavior on refinement levels [Formula: see text], whereas for three dimensions, only the constant coefficient problem in a unit cube is considered. The numerical results are complete up to polynomial order [Formula: see text], and for [Formula: see text] and [Formula: see text] smoothness.

Molecular evidence of transient therapeutic effectiveness of natalizumab despite high-titre neutralizing antibodies.

Natalizumab is a humanized monoclonal antibody directed against the alpha-4 integrin subunit of very late activation antigen-4 (VLA-4). Natalizumab neutralizing antibodies (NAB) have been found to significantly reduce beneficial effects of natalizumab treatment in multiple sclerosis. We investigated interactions of NAB with natalizumab by serial measurements of alpha-4 integrin levels on peripheral blood mononuclear cells using flow cytometry. In addition, serum concentrations of soluble vascular cell adhesion molecule-1 (sVCAM-1), the endothelial ligand of VLA-4, and serum NAB were serially determined. Natalizumab infusion led to a transient reduction in alpha-4 integrin levels on immune cells and serum sVCAM-1 levels along with serum negativity of NAB lasting for a few days post-infusion. Apparently, the high-dose effect of freshly infused natalizumab resulted in a transient neutralization of NAB possibly involving a transient therapeutic effectiveness.

Mutation analysis in 54 propionic acidemia patients.

Deficiency of propionyl CoA carboxylase (PCC), a dodecamer of alpha and beta subunits, causes inherited propionic acidemia. We have studied, at the molecular level, PCC in 54 patients from 48 families comprised of 96 independent alleles. These patients of various ethnic backgrounds came from research centers and hospitals in Germany, Austria and Switzerland. The thorough clinical characterization of these patients was described in the accompanying paper (Grünert et al. 2012). In all 54 patients, many of whom originated from consanguineous families, the entire PCCB gene was examined by genomic DNA sequencing and in 39 individuals the PCCA gene was also studied. In three patients we found mutations in both PCC genes. In addition, in many patients RT-PCR analysis of lymphoblast RNA, lymphoblast enzyme assays, and expression of new mutations in E.coli were carried out. Eight new and eight previously detected mutations were identified in the PCCA gene while 15 new and 13 previously detected mutations were found in the PCCB gene. One missense mutation, p.V288I in the PCCB gene, when expressed in E.coli, yielded 134% of control activity and was consequently classified as a polymorphism in the coding region. Numerous new intronic polymorphisms in both PCC genes were identified. This study adds a considerable amount of new molecular data to the studies of this disease.

Propionic acidemia: neonatal versus selective metabolic screening.

BACKGROUND: Whereas propionic acidemia (PA) is a target disease of newborn screening (NBS) in many countries, it is not in others. Data on the benefit of NBS for PA are sparse. STUDY DESIGN: Twenty PA patients diagnosed through NBS were compared to 35 patients diagnosed by selective metabolic screening (SMS) prompted by clinical findings, family history, or routine laboratory test results. Clinical and biochemical data of patients from 16 metabolic centers in Germany, Austria, and Switzerland were evaluated retrospectively. Additionally, assessment of the intelligent quotient (IQ) was performed. In a second step, the number of PA patients who have died within the past 20 years was estimated based on information provided by the participating metabolic centers. RESULTS: Patients diagnosed through NBS had neither a milder clinical course regarding the number of metabolic crises nor a better neurological outcome. Among NBS patients, 63% were already symptomatic at the time of diagnosis, and <10% of all patients remained asymptomatic. Among all PA patients, 76% were found to be at least mildly mentally retarded, with an IQ <69. IQ was negatively correlated with the number of metabolic decompensations, but not simply with the patients' age. Physical development was also impaired in the majority of patients. Mortality rates tended to be lower in NBS patients compared with patients diagnosed by SMS. CONCLUSION: Early diagnosis of PA through NBS seems to be associated with a lower mortality rate. However, no significant benefit could be shown for surviving patients with regard to their clinical course, including the number of metabolic crises, physical and neurocognitive development, and long-term complications.

Isolated leptomeningeal infiltration of a primary CNS B-cell lymphoma diagnosed by flow cytometry and confirmed by necropsy.

BACKGROUND: The diagnosis of the isolated leptomeningeal involvement of a primary central nervous system B-cell lymphoma without parenchyma lesions may be difficult. Patients with leptomeningeal meningeosis lymphomatosa can present with various neurologic deficits. AIMS OF THE STUDY: To demonstrate the impact of cerebrospinal fluid (CSF) flow cytometry in the diagnosis of an isolated leptomeningeal manifestation of B-cell lymphoma by presenting an interesting case report. METHODS: Flow cytometric analysis of B-cell monoclonality of the CSF was performed as complementary diagnostic procedure in addition to CSF cytology. Final diagnosis was confirmed by necropsy. RESULTS: We suspected isolated leptomeningeal manifestation of B-cell lymphoma with palsy of the VI and VII cranial nerves in a 79-year-old male, because of mononuclear pleocytosis in CSF. Interestingly, the decisive diagnostic hint was given by implementation of flow cytometry of the CSF. Diagnosis was confirmed by postmortem autopsy. CONCLUSION: Our case shows that flow cytometry of the CSF in addition to conventional CSF cytology has the potential to accelerate diagnosis of lymphomeningeal infiltration of B-cell lymphoma.

New protease inhibitors prevent gamma-secretase-mediated production of Abeta40/42 without affecting Notch cleavage.

We have designed new non-peptidic potential inhibitors of gamma-secretase and examined their ability to prevent production of amyloid-beta 40 (Abeta40) and Abeta42 by human cells expressing wild-type and Swedish-mutant beta-amyloid precursor protein (betaAPP). Here we identify three such agents that markedly reduce recovery of both Abeta40 and Abeta42 produced by both cell lines, and increase that of C99 and C83, the carboxy-terminal fragments of betaAPP that are derived from beta-and alpha-secretase, respectively. Furthermore, we show that these inhibitors do not affect endoproteolysis of endogenous or overexpressed presenilins. These inhibitors are totally unable to affect the mDeltaEnotch-1 cleavage that leads to generation of the Notch intracellular domain (NICD). These represent the first non-peptidic inhibitors that are able to prevent gamma-secretase cleavage of betaAPP without affecting processing of mDeltaEnotch-1 or endoproteolysis of presenilins. The distinction between these two proteolytic events, which are both prevented by disruption of presenilin genes, indicates that although they are intimately linked with betaAPP and Notch maturation, presenilins are probably involved in the control of maturation processes upstream of enzymes that cleave gamma-secretase and Notch.

Adhesion molecules are promising candidates to establish surrogate markers for natalizumab treatment.

BACKGROUND: Natalizumab is the first monoclonal antibody therapy approved for multiple sclerosis (MS). Its therapeutic mechanism is the blockade of the α4-integrin subunit of the adhesion molecule (AM) very late activation antigen-4 (VLA-4), which leads to an inhibition of immune cell extravasation into the central nervous system (CNS). METHODS: We investigated changes in the expression levels of unblocked α4-integrin and further AM (intercellular adhesion molecule-1, -2, -3 (cICAM-1, -2, -3), leukocyte function associated antigen-1 (LFA-1)) on peripheral blood mononuclear cells (PBMC) determined by flow cytometry from 25 patients with MS before the first natalizumab infusion and before the fourth infusion. In 15 MS patients AM expression was evaluated every 3 months over 1 year. RESULTS: We found a significant decrease (p < 0.0001) of unblocked α4-integrin cell surface expression on all investigated PBMC subsets (T cells -61.7%, B cells -69.1%, monocytes/macrophages -46.4%) in the blood of MS patients after 3 months of natalizumab treatment. Moreover, a continuous decrease (p < 0.05) of unblocked α4-integrin expression levels was seen after 3, 6, 9, and 12 months. As a secondary effect, expression levels of the other investigated AM were differentially affected. CONCLUSIONS: Results show a sustained decrease of unblocked α4-integrin expression not only in all patients but also in all investigated PBMC subsets. This probably results in a continuously decreasing transmigration of PBMC into the CNS and may explain the improved clinical efficacy in the second treatment year and also the increasing risk of progressive multifocal leukoencephalopathy during long-term natalizumab therapy. We conclude that AM expression profiles are promising candidates for the development of a biomarker system to determine both natalizumab treatment response and patients at risk for opportunistic CNS infections.

Relationship between thrombin generation and carotid intima-media thickness.

UNLABELLED: Increasing evidence indicates that thrombin plays a role not only in thrombosis but also in the progression of atherosclerosis. AIM: The relationship between thrombin generation and intima-media thickness (IMT) as an index of subclinical atherosclerosis was investigated. Participants, material, methods: We examined 163 asymptomatic middle-aged persons free of overt clinical atherosclerotic disease. They underwent ultrasonography of the common carotid arteries. In addition, thrombin generation was measured by means of CAT (calibrated automated thrombography). For our study we divided the healthy study participants into three age groups (<45, 45-60 and >60 years). RESULTS: A significant positive correlation was seen between endogenous thrombin potential (ETP) (p = 0.012), time to peak (TTP) (p = 0.033) start tail (p = 0.007) and carotid IMT in the group of healthy volunteers younger than 45 years. CONCLUSION: We demonstrated that in adults younger than 45 years without clinically overt atherosclerotic disease ETP was significantly associated with carotid IMT. It is tempting to speculate that ETP may serve as an index for subclinical atherosclerosis in persons below 45 years.