A Sequence of Phase Transformations and Phases in NiCoFeCrGa High Entropy Alloy

The present investigation is directed to phase transitions in the equimolar NiCoFeCrGa high entropy alloy, which is a mixture of face-centered cubic (FCC) and body-centered cubic (BCC) crystalline phases. The microstructure of the samples was investigated by using scanning electron microscopy (SEM), time-of-flight secondary ion mass spectroscopy (TOF-SIMS), transmission electron microscopy-based energy-dispersive spectroscopy (EDS) and electron energy loss spectroscopy (EELS), as well as X-ray diffraction (XRD) measurements. Based on the phases observed in different temperature ranges, a sequence of the phase transitions can be established, showing that in a realistic process, when freely cooling the sample with the furnace from high to room temperature, a microstructure having spinodal-like decomposition can also be expected. The elemental mapping and magnetic behaviors of this decomposed structure are also studied.

Commentary to the recently published review "Drug pipeline in neurodegeneration based on transgenic mice models of Alzheimer's disease" by Li, Evrahimi and Schluesener. Ageing Res. Rev. 2013 Jan;12(1):116-40

Li and colleagues summarized the most frequently used Alzheimer's disease (AD) mouse models available for drug testing and the mediating effects of the different compounds. With almost 300 cited publications, authors present the research community's effort of the last 10 years in finding a new drug for the treatment of AD. Some of the transgenic mouse lines mentioned by Li and colleagues are discussed only very briefly. Since we are convinced that a couple of these models indeed have a great value for AD research and the development of new AD drugs we will subsequently describe a few of them in more detail. A suitable mouse model of AD does not only have to mimic major hallmarks of AD that are modifiable by different test substances as mentioned by the authors; they also have to be translational to clinical trials in humans. For the following discussion, we will therefore also include information on clinical trials of drugs previously tested in the different transgenic mice.

Acute Cerebrovascular Disease in the Young

Background and Purpose—

Strokes have especially devastating implications if they occur early in life; however, only limited information exists on the characteristics of acute cerebrovascular disease in young adults. Although risk factors and manifestation of atherosclerosis are commonly associated with stroke in the elderly, recent data suggests different causes for stroke in the young. We initiated the prospective, multinational European study Stroke in Young Fabry Patients (sifap) to characterize a cohort of young stroke patients.

Methods—

Overall, 5023 patients aged 18 to 55 years with the diagnosis of ischemic stroke (3396), hemorrhagic stroke (271), transient ischemic attack (1071) were enrolled in 15 European countries and 47 centers between April 2007 and January 2010 undergoing a detailed, standardized, clinical, laboratory, and radiological protocol.

Results—

Median age in the overall cohort was 46 years. Definite Fabry disease was diagnosed in 0.5% (95% confidence interval, 0.4%–0.8%; n=27) of all patients; and probable Fabry disease in additional 18 patients. Males dominated the study population (2962/59%) whereas females outnumbered men (65.3%) among the youngest patients (18–24 years). About 80.5% of the patients had a first stroke. Silent infarcts on magnetic resonance imaging were seen in 20% of patients with a first-ever stroke, and in 11.4% of patients with transient ischemic attack and no history of a previous cerebrovascular event. The most common causes of ischemic stroke were large artery atherosclerosis (18.6%) and dissection (9.9%).

Conclusions—

Definite Fabry disease occurs in 0.5% and probable Fabry disease in further 0.4% of young stroke patients. Silent infarcts, white matter intensities, and classical risk factors were highly prevalent, emphasizing the need for new early preventive strategies.

Clinical Trial Registration Information—

URL: http://www.clinicaltrials.gov .Unique identifier: NCT00414583

Longitudinal magnetization transfer imaging in mild to severe Alzheimer disease

BACKGROUND AND PURPOSE

MTI has been proposed as a sensitive technique for studying microstructural brain tissue changes in patients with AD, but the course of these changes over time is largely unknown. We therefore used a placebo-controlled study of memantine to follow the evolution of tissue damage in AD by means of MTR measurements and investigated how MTR changes were related to brain atrophy and cognition.

MATERIALS AND METHODS

Twenty-eight patients (76.5 ± 5.8 years) with mild to moderate AD underwent MTI, brain volume measurements, and cognitive testing at baseline and after 6 and 12 months. Nineteen healthy individuals (73.3 ± 3.2 years) served as controls. MTI was performed with a 2-minute protocol that was optimized for an enhanced MT effect and reduced motion sensitivity. Global and regional MTR measurements served as correlations with brain volumes and the MMSE score.

RESULTS

AD patients had significantly lower global MTR values than controls, and showed a consistent and significant MTR reduction in all regions investigated over a period of 12 months. These MTR changes were paralleled by a brain tissue loss of 2.2% per year. Associations between MTR and cognition were found for the hippocampus, putamen, and thalamus, and were more pronounced in the left hemisphere.

CONCLUSIONS

MTI in AD allows the assessment of ongoing global and regional brain damage independent of atrophy, and therefore appears to be a valuable marker for disease-related tissue changes.

Seroprevalence of Histomonas meleagridis in pullets and laying hens determined by ELISA

Serum samples from 1120 layers from 56 flocks and 400 pullets from 20 flocks were tested by an indirect sandwich ELISA to investigate the prevalence of antibodies to Histomonas meleagridis in chickens kept in alternative husbandry systems. The overall prevalence of antibodies to H meleagridis in layers was 37.3 per cent, and positive birds were identified in 50 flocks. This was significantly higher than in pullets, where only 8.3 per cent of the birds tested positive. Optical density (OD) values obtained from pullet sera were much lower than the OD values from layers; however, positive birds were detected in half of the pullet flocks. In particular, all birds from an organic pullet flock were found to be positive, with high OD values. Overall, the highest prevalence of positive sera was obtained from birds kept in free-range flocks. Attempts to reisolate live histomonads from birds in 18 layer flocks were unsuccessful.

Experimental infection of chickens with Histomonas meleagridis confirms the presence of antibodies in different parts of the intestine

Specific pathogen-free chickens were infected with a clonal culture of the protozoan parasite, Histomonas meleagridis. Severe lesions were found within the caeca of all birds euthanized at 7 and 14 days post-infection (d.p.i.). Following necropsy of birds, intestinal samples were taken to establish ex vivo tissue cultures to determine the IgG, IgA and IgM antibody levels in the supernatants before and after incubation with a recently established ELISA. Presence of antibodies was also determined in the sera and first optical density values for IgG above the cut-off were detected at 14 d.p.i. IgA levels remained low in the serum with a small peak 4 weeks p.i., a phenomenon also found for IgM. The intestinal tissue samples showed very strong immunological reactions in the parasitized caeca with an initial peak of IgM, high levels of IgG and a continuous increase of IgA. In the duodena and jejuna, IgA values reached similar high levels as those obtained in the caeca, whereas IgG and IgM increased only slightly.

CHF5074, a novel gamma-secretase modulator, attenuates brain beta-amyloid pathology and learning deficit in a mouse model of Alzheimer's disease

BACKGROUND AND PURPOSE

We evaluated the effects of 1-(3',4'-dichloro-2-fluoro[1,1'-biphenyl]-4-yl)-cyclopropanecarboxylic acid (CHF5074), a new gamma-secretase modulator, on brain beta-amyloid pathology and spatial memory in transgenic mice expressing the Swedish and London mutations of human amyloid precursor protein (hAPP).

EXPERIMENTAL APPROACH

Sixty 6-month-old hAPP mice were treated for 6 months with CHF5074 or ibuprofen (375 ppm in the diet) or standard diet. Twenty-one wild-type mice received standard diet.

KEY RESULTS

Compared with transgenic controls, CHF5074 treatment significantly reduced the area occupied by plaques in cortex (P = 0.003) and hippocampus (P = 0.004). The number of plaques were also reduced by CHF5074 in both cortex (P = 0.022) and hippocampus (P = 0.005). Plaque-associated microglia in CHF5074-treated animals was lower than in transgenic controls in cortex (P = 0.008) and hippocampus (P = 0.002). Ibuprofen treatment significantly reduced microglia area in cortex and hippocampus but not beta-amyloid burden. On the last day of the Morris water maze, transgenic controls performed significantly worse than the non-transgenic animals and the CHF5074-treated transgenic mice, on the swimming path to reach the hidden platform. Ibuprofen-treated animals did not perform significantly better than transgenic controls.

CONCLUSIONS AND IMPLICATIONS

Chronic CHF5074 treatment reduced brain beta-amyloid burden, associated microglia inflammation and attenuated spatial memory deficit in hAPP mice. This novel gamma-secretase modulator is a promising therapeutic agent for Alzheimer's disease.

Randomized, crossover, single-blind, placebo-controlled, human pharmacology clinical trial with desoxypeganine, a new cholinesterase and selective MAO-A inhibitor: multiple-dose pharmacokinetics

Desoxypeganine, a naturally occurring alkaloid, is being developed for its potential utility in the pharmacological treatment of alcohol abuse to reduce craving and depression in alcohol abusers, and might also be useful as a smoking cessation aid. During the preclinical development it was characterized as a cholinesterase inhibitor, acting preferentially on butyrylcholinesterase, and as a selective inhibitor of monoamine oxidase A but not monoamine oxidase B.

OBJECTIVE

The aim of the present human pharmacology clinical trial was to assess the oral bioavailability, pharmacokinetic profile and tolerability of desoxypeganine, administered in a multiple-dose regimen to healthy volunteers.

SUBJECTS AND METHODS

Eighteen healthy adult volunteers of both sexes received placebo, 50 mg and 100 mg desoxypeganine (b.i.d. for 3 days) in a single-blind, crossover, randomized manner. Main pharmacokinetic parameters after single and multiple doses were estimated. Clinical tolerability and clinical laboratory safety, including effect on QTc interval, were assessed.

RESULTS

Non-compartmental estimations of Cmax, AUC, tmax, t1/2 and MRT at 12-h intervals are given. No significant dose effect was observed in tmax, t1/2 and MRT. Cmax and AUC are approximately double with the dose of 100 mg comparing with the dose of 50 mg. A significant increase (p < 0.05) on Cmax and AUC was also obtained with the highest dose administered in comparison with the lowest one, revealing a slight but clinically insignificant accumulation. Steady state of drug concentration was reached in both genders during the study period. Plasma protein binding of desoxypeganine amounted to approximately 18%. No severe adverse events were recorded and none of the subjects suffered from any adverse event that led to withdrawal from the study. Most frequently recorded adverse event was dizziness. No significant effects of desoxypeganine on vital signs, laboratory parameters or QTc interval were observed.

CONCLUSIONS

The present clinical trial describes the pharmacokinetic profile of two doses of desoxypeganine, administered orally in multiple dose to healthy volunteers. The drug was well tolerated without any severe clinical, clinical laboratory, or ECG adverse events being recorded.

Establishing an indirect sandwich enzyme-linked-immunosorbent-assay (ELISA) for the detection of antibodies against Histomonas meleagridis from experimentally infected specific pathogen-free chickens and turkeys

No serological method suitable for large screening of antibodies against Histomonas meleagridis in poultry is available so far, the objective targeted in the present investigation. Consequently, an ELISA was developed as a suitable tool for this purpose. Investigating serum samples from non-infected specific pathogen-free (spf) chickens and commercial turkeys a high-background signal was noticed when ELISA plates were directly coated with purified parasitic cells. This signal was significantly reduced by coating the plates with a polyclonal rabbit antibody, raised against histomonads, prior to the addition of the antigen. Adopting this approach five antigen preparations were compared and a high reproducibility could be demonstrated reflected by a very low coefficient of variation of 5.3% and 1.7% for the chicken and turkey sera, respectively. After this initial development all further experiments were carried out with one set of plates and the same antigen preparation. Investigating chicken sera obtained from birds infected at 14 days of life, OD values above a predetermined cut-off value were observed 2 weeks post-infection and a rise of IgG antibodies was noticed until 6 weeks post-infection, when the experiment was terminated. Non-protected turkeys infected at 6 weeks of age displayed an increasing IgG response until 14 days post-infection, prior to the death of animals due to histomonosis. In comparison, the majority of turkeys vaccinated with attenuated histomonads, obtained through prolonged passaging and challenged 4 weeks later with virulent parasites, displayed a demonstrable antibody response after the challenge only. Antibody titres increased until 4 weeks post-challenge when the birds were killed and the study was terminated. Altogether, the developed indirect sandwich ELISA proved to be a quick and efficient method to detect IgG antibodies against H. meleagridis in sera of experimentally infected chickens and turkeys and will be a helpful tool to obtain more insights into the epidemiology of the parasite and the immune response of its hosts.

Longitudinal multimodal imaging in mild to moderate Alzheimer disease: a pilot study with memantine

OBJECTIVE

To study the feasibility of multimodal neuroimaging in mild to moderate Alzheimer disease (AD) and to estimate the size of possible treatment effects of memantine on potential functional, structural and metabolic biomarkers of disease progression.

METHODS

In this randomised, double-blind, placebo-controlled pilot study, 36 patients with moderate AD received 52 weeks of memantine (20 mg/day) or placebo. Patients were re-evaluated after 26 and 52 weeks to measure the change from baseline in several outcome measures including global and regional glucose metabolism, total brain and hippocampal volumes, as well as chemical shift imaging-derived global and regional N-acetylaspartate and myoinositol concentrations.

RESULTS

In the total population, global glucose metabolism decreased by 2.3% (p<0.01), total brain volume by 2.1% (p<0.001) and hippocampal volume by 2.7% (p<0.01) after 52 weeks. Chemical shift imaging (CSI) spectra were severely affected by patient-induced artefacts and highly variable. Patients receiving memantine showed less decline in glucose metabolism in all brain areas than patients on placebo. Their loss of hippocampal volume was substantially smaller (2.4% vs 4.0%). No between-group differences were seen for changes in total brain volume.

CONCLUSIONS

The results support the use of multimodal imaging including MRI and positron emission tomography (PET) to monitor the progression of moderate AD. CSI yielded unreliable longitudinal results. The data suggest that memantine has potentially protective effects in AD and they can be used for planning larger confirmatory studies on the cerebral effects of memantine.

The role of alpha-synuclein in neurodegenerative diseases: a potential target for new treatment strategies?

Alpha-synuclein (AS) is the main constituent of Lewy bodies. There is an ongoing discussion if overexpression is already dangerous, or if toxicity is subjected to oligomers, protofibrils or mature aggregates. The facts that the central hydrophobic part of AS is also a constituent of amyloid plaques in Alzheimer's disease (AD) and that a majority of patients have Lewy bodies and Lewy neurites in specific brain areas raised our interest in the contribution of AS to AD pathogenesis. The N-terminal amino acid sequence 1-15 of beta-synuclein (BS) seems to be a natural antiaggregation factor for AS. We synthesized a library with different sequence variations. Several of these peptides displayed neuroprotective activity in tissue culture models of neurodegeneration induced by oxidative stress or beta-amyloid 1-42. In spite of the fact that these peptides have a short half-life, a significant in vivo reduction in brain plaque load and improvement of behavior was demonstrated in amyloid precursor protein transgenic mice after intranasal treatment for 2 months. KEGV, the shortest sequence, was also active after intraperitoneal application. The in vitro effects cannot be explained by the antiaggregatory potential, but most likely by interaction of BS derivates with antiapoptotic PI3/Akt or antioxidative pathways. The possibility that BS-derived peptidomimetics act as neuroprotectants and prevent protein misfolding suggests therapeutic usefulness.

Is alpha-Synuclein Pathology a Target for Treatment of Neurodegenerative Disorders?

Alpha-synuclein is the main constituent of intra-neuronal Lewy bodies, which are characteristic of Parkinson's disease, but aggregates are also found as axonal inclusions. Alpha-synuclein pathology is found together with beta-amyloid plaques and neurofibrillary tangles in Alzheimer's disease and other neurodegenerative disorders. In spite of the fact that the biological function of this synaptic protein is not known so far, there is an increasing body of evidence indicating an interaction with amyloid peptides, but also with tau-hyperphosphorylation. A high proportion of alpha-synuclein purified from Lewy bodies is phosphorylated on Ser129. There are still different opinions about the toxicity of the alpha-synuclein aggregates. Alpha-synuclein seems to influence different intracellular signaling pathways which are in direct relation to defense mechanisms against reactive oxygen species or apoptosis. It is obvious that overproduction of alpha-synuclein, but also different mutations, are inducing the formation of aggregates. Because of the possible link to neurodegeneration, different attempts have been made to counteract alpha-synuclein aggregation. An interesting approach is utilizing beta-synuclein, a biological factor, with an aminoacid sequence closely resembling that of alpha-synuclein. Proof of concept studies indicated that overexpression of beta-synuclein is able to counteract alpha-synuclein aggregation in a transgenic animal model, while also ameliorating functional deficits. As an alternative approach, the use of low molecular beta-synuclein N-terminal peptide derivatives has been considered. Several of these structures displayed clear neuroprotective activities in tissue culture models of neurodegeneration, including beta-amyloid toxicity. Therefore it has been speculated that these compounds might have a broad therapeutic efficacy in different neurodegenerative disorders. A proof of concept study in hAPP-transgenic animals resulted in a highly significant decrease in beta-amyloid plaque load, an increase in soluble beta-amyloid peptides and a decrease in insoluble forms. There was also significant improvement of cognitive deficits in this APP transgenic mouse model following intranasal but also peripheral treatment with three of these compounds. From this study it is concluded that the observed effects of the peptides derived from beta-synuclein N-terminus are depending on both, a direct interaction with aggregation of proteins, but also with stimulation of anti-apoptotic and anti-oxidative intracellular signaling pathways.

Neuropeptide dietary supplement N-PEP-12 enhances cognitive function and activates brain bioelectrical activity in healthy elderly subjects

N-PEP-12 is a dietary supplement consisting of neuropeptides and amino acids. In animal experiments, the compound has been shown to enhance cognitive function and reduce neurodegenerative events associated with aging. In this study, we investigated the effects of a single oral dose of N-PEP-12 (180 mg) on brain bioelectrical activity and cognitive performance in healthy elderly subjects. N-PEP-12 induced a significant (p < 0.05) increase in relative alpha-activity power 6 h after administration. This enhancement was accompanied by a generalized decrease in slow Delta-activity. Significant improvement in memory performance subtests was also seen 6 h after N-PEP-12 administration in some but not in all tests. Taken together, these data suggest that N-PEP-12 might be a reliable dietary supplement to be investigated for improving and, perhaps, maintaining brain function among healthy older adults.

Neuroprotection of Cerebrolysin in tissue culture models of brain ischemia: post lesion application indicates a wide therapeutic window

All attempts to reduce neuronal damage after acute brain ischemia by the use of neuroprotective compounds have failed to prove efficacy in clinical trials so far. One of the main reasons might be the relatively narrow time window for intervention. In this study 2 different tissue culture models of ischemia, excitotoxic lesion by the use of glutamate and oxygen-glucose deprivation (OGD), were used to investigate the effects of delayed application of Cerebrolysin (Cere) on neuronal survival. This drug consists of low molecular weight peptides with neuroprotective and neurotrophic properties similar to naturally occurring growth factors. After both types of lesion, acute as well as delayed treatment with Cere resulted in a dose dependent and significant rescue of neurons. In the model of excitotoxic cell death significant drug effects were found even when the treatment started with a delay of 96 hours after addition of glutamate. In the OGD model pronounced effects were found after 48 hours delay of treatment, and even after 72 hours a small but significant rescue of neurons was detected. The neuroprotective effects of a single addition of Cerebrolysin to the culture medium resulted in significant protection until end of the experiments which was up to 2 weeks after the initial lesion. A shift of the efficacious dosages from low to high concentrations indicates that most likely active compounds are used up, indicating that multiple dosing might even increase the effect size. In conclusion the results indicate that Cere displays a relatively wide therapeutic time window which might be explained by a combination of acute neuroprotective properties and neurotrophic efficacy.

A peptide preparation protects cells in organotypic brain slices against cell death after glutamate intoxication

Cerebrolysin has been shown to have neurotrophic and neuroprotective potential similar to NGF or BDNF. In the present study organotypic brain slices were utilized to determine the neuroprotective effects of Cerebrolysin, in a glutamate lesion paradigm mimicking a key event in ischemia. The study focused on the effects of Cerebrolysin on both necrotic and apoptotic cell death. Two specific DNA intercalating dyes were used to distinguish the type of cell death. The drug effect was evaluated both microscopically and quantitatively before, 24 hours after and then again 8 days after the lesion. Cerebrolysin was added either before and after the lesion or after the lesion only. The most pronounced effect was seen with the drug added both prior to and after the glutamate lesioning. A treatment after the lesion only also counteracted necrosis and apoptosis. The results render the drug relevant for treating acute as well as chronic neurodegenerative diseases.

N-PEP-12 – a novel peptide compound that protects cortical neurons in culture against different age and disease associated lesions

The neuroprotective potency of N-PEP-12, a novel, proprietary compound consisting of biopeptides and amino acids was investigated. Lesion models have been applied in neuronal cultures of embryonic chicken cortex, pre-treated with N-PEP-12 from the first day onwards. On day 8 in vitro neurons were lesioned and cell viability was measured 24 and 48 hours later. To simulate acute brain ischemia, cytotoxic hypoxia was induced by sodium cyanide or by iodoacetate and excitotoxicity by L-glutamate. Ionomycin for up to 48 hours induced calcium overload. The cytoskeleton was disrupted by addition of colchicine. N-PEP-12 shows dose-dependent neuroprotection in all different models. The effect size depends on the recovery time but also on the extent of the lesion. In cases of mild to moderate lesion pronounced dose-dependent effects could be demonstrated. This indicates that chronic exposure to N-PEP-12 is able to prevent neuronal cell death associated to conditions occurring during normal aging and neurological disorders like ischemic stroke, hypoxia, brain trauma, or AD.

Polymorphic microsatellite markers in the outbred CFW and ICR stocks for the generation of speed congenic mice on C57BL/6 background

Reliable definition of the phenotype of particular alleles is carried out in the genetic background of inbred strains. Appearance of mutations in outbred mice therefore requires the generation of congenic mice. The aim of this study was the establishment of a list of polymorphic microsatellite markers which can be used in a polymerase chain reaction (PCR)-based marker-assisted selection protocol (MASP) to allow the use of the two common outbred stocks, CFW and ICR, as donor animals for the fast generation of congenic C57BL/6 mice. The selection of informative microsatellite markers was carried out to provide a simple evaluation of the PCR products by conventional agarose gel electrophoresis. Outbred mice from three suppliers were examined. In total, 153 microsatellite loci were analysed. Here we present 76 and 70 microsatellite markers polymorphic for the outbred ICR and CFW stocks compared to C57BL/6. At least three microsatellite loci per chromosome were chosen as informative markers for the autosomal genome, giving rise to a maximum marker distance of 58 cM. Thus, additional individual markers have to be selected for the respective outbred mouse which is chosen as a donor animal.

Amelioration of the cerebrovascular amyloidosis in a transgenic model of Alzheimer?s disease with the neurotrophic compound Cerebrolysin?

Increased production and reduced clearance of amyloid beta (Abeta) plays a central role in the pathogenesis of Alzheimer's disease (AD). We have recently shown that the neurotrophic peptide mixture Cerebrolysin (Cbl) has the ability of improving synaptic functioning and reducing amyloid deposition in a transgenic (tg) animal model of Alzheimer's disease (AD). Since in AD, potentially toxic Abeta aggregates accumulate not only around neurons but also in the blood vessels, then it is important to investigate whether bioactive compounds such as Cbl might have the capacity to ameliorate the age-related cerebral amyloid angiopathy (CAA) in tg models. To this end, tg mice expressing mutant human amyloid precursor protein (APP) under the Thy1 promoter were treated with Cbl or saline alone starting at 7 or 12 months of age for a total of three months. Neuropathological analysis with an antibody against Abeta showed that Cbl decreased amyloid deposition around the blood vessels in a time dependent manner. These effects were accompanied by a reduction in perivascular microgliosis and astrogliosis and increased expression of markers of vascular fitness such as CD31 and ZO-1. No lymphocytic infiltration was observed associated with Abeta in the vessels. Consistent with these findings, ultrastructural analysis showed that while in tg mice treated with saline alone there was an abundant accumulation of amyloid fibers in the vascular wall accompanied by thickening of the basal membrane and endothelial cell damage, in Cbl-treated mice there was considerable reduction in the subcellular alterations of endothelial and smooth muscle cells with preservation of basal membranes and intercellular junctions. Taken together, these results suggest that Cbl treatment might have beneficial effects in patients with cognitive impairment due to cerebrovascular amyloidosis by reducing Abeta accumulation and promoting the preservation of the cerebrovasculature.

The neuroprotective effects of Cerebrolysin? in a transgenic model of Alzheimer?s disease are associated with improved behavioral performance

Cerebrolysin is a peptide mixture with neurotrophic effects that might have the ability of both reducing amyloid burden and improving synaptic plasticity in Alzheimer's disease (AD). In order to determine if Cerebrolysin is capable of ameliorating the neurodegenerative and behavioral alterations associated with amyloid beta (A beta) production; transgenic (tg) mice expressing mutant human amyloid precursor protein (APP) under the Thy1 promoter were treated with Cerebrolysin or saline alone starting at 3 or 6 months of age for a total of three months. Animals were then tested behaviorally (at 6 and 9 months of age respectively) in the water maze and then analyzed neuropathologically for amyloid burden, synaptic density, astrogliosis and apoptosis. Performance analysis in the water maze showed that in the younger tg mice cohort, Cerebrolysin treatment significantly ameliorated the performance deficits. In the older cohort, there was a trend toward improved performance in the learning curve. Neuropathological examination showed that in both age/treatment groups, Cerebrolysin promoted synaptic regeneration, and reduced the proportion of neurons displaying DNA fragmentation by the (TdT)-mediated dUTP-biotin nick-end labeling (TUNEL) method. Moreover, Cerebrolysin treatment reduced A beta burden by 43% in the young group and by 27% in the older group. Taken together, these results suggest that Cerebrolysin treatment might have beneficial effects in patients with cognitive impairment by reducing A beta accumulation and promoting the preservation of synaptic terminals.

Current drugs and future hopes in the treatment of Alzheimer's disease

In spite of several years of experience with the use of cholinesterase inhibitors for treatment of symptoms of Alzheimer's disease their influence on disease progression remains still unclear. New cholinesterase inhibitors should provide an additional neuroprotective activity, because only substances which stop neuronal death can influence disease progression. New treatment strategies are focusing on amyloid processing, preventing the occurrence of toxic A beta(1-42) peptide. These procedures include the vaccination trials, but their clinical usefulness has to be proven. Also strategies focussing on neurofibrillary pathologies should be explored in detail. Drug development for Alzheimer's disease should include all pathological events associated with neurodegeneration, like oxidative stress, neuroinflammation or disturbances in growth factor signaling. Abnormal protein aggregation as a common feature of different neurodegenerative diseases might also be a promising drug target. Beside beta sheet breakers directed against beta-amyloid deposition the endogenous protein beta-synuclein or derivatives of it might be able to counteract aggregation of alpha-synuclein as well as of amyloid beta protein. Interaction with alpha-synuclein deserves special attention because it might be an early step of synaptic degeneration. Due to the complexity of the disease combination of different drugs might be the most promising way to go. The parallel development of early biological markers should enable intervention in pre-symptomatic disease stages.

Effects of Cerebrolysin on amyloid-beta deposition in a transgenic model of Alzheimer's disease

We investigated the potential mechanisms through which Cerebrolysin, a neuroprotective noothropic agent, might affect Alzheimer's disease pathology. Transgenic (tg) mice expressing mutant human (h) amyloid precursor protein 751 (APP751) cDNA under the Thy-1 promoter (mThy1-hAPP751) were treated for four weeks with this compound and analyzed by confocal microscopy to asses its effects on amyloid plaque formation and neurodegeneration. In this model, amyloid plaques in the brain are found much earlier (beginning at 3 months) than in other tg models. Quantitative computer-aided analysis with anti-amyloid-beta protein (A beta) antibodies, revealed that Cerebrolysin significantly reduced the amyloid burden in the frontal cortex of 5-month-old mice. Furthermore, Cerebrolysin treatment reduced the levels of A beta(1-42). This was accompanied by amelioration of the synaptic alterations in the frontal cortex of mThy1-hAPP751 tg mice. In conclusion, the present study supports the possibility that Cerebrolysin might have neuroprotective effects by decreasing the production of A beta(1-42) and reducing amyloid deposition.

Vitamin E binding protein afamin protects neuronal cells in vitro

Afamin, an 87 kDa human plasma glycoprotein with specific binding properties for vitamin E (alpha-tocopherol) was recently characterized (Jerkovic, 1997; Vögele, 1999). In the present study the in vitro effects on neuronal cells of native human Afamin, of Afamin pre-loaded with vitamin E (Afamin+), and of vitamin E were investigated. Isolated cortical chicken neurons were maintained either under apoptosis-inducing low serum conditions or exposed to oxidative stress by the addition of H2O2 or beta-amyloid peptide(25-35). Afamin and vitamin E synergistically enhance the survival of cortical neurons under apoptotic conditions. Furthermore, Afamin alone protects cortical neurons from cell death in both experimental settings. Therefore, the plasma glycoprotein Afamin apparently displays a neuroprotective activity not only by virtue of binding and transporting vitamin E but also on its own.

Cerebrolysin in Alzheimer's disease: a randomized, double-blind, placebo-controlled trial with a neurotrophic agent

Cerebrolysin (Cere) is a compound with neurotrophic activity. It has been shown to be effective in the treatment of Alzheimer's disease (AD) in earlier trials. In this multicenter, randomized, double-blind, placebo-controlled, parallel-group study, patients were injected intravenously with placebo or 30 mL Cere five days per week for four weeks. Effects on cognition and global function were evaluated with the Alzheimer Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) and the Clinicians Interview-based Impression of Change with Caregiver Input scale (CIBIC+) 4, 12, 24 weeks after the beginning of the injections. 192 patients were enrolled, 95 were randomized to placebo, and 97 to Cere. At baseline, there was a significant difference between groups for age, age of onset of dementia, and the number of patients with hallucinations. At week 12 there was a significant difference on the CIBIC+ (p = 0.033) in favor of Cere. The number of CIBIC+ responders (score < or = 4), was significantly higher (p = 0.007), with 68 (76%) in the Cere group and 51 (57%) in the placebo group. Trends were noted in the Disability Assessment in Dementia scale and the Cornell Depression Scale. Adverse events were recorded in 73% of placebo and 64% of Cere patients. Most common adverse events were headaches, dizziness, weight loss and anxiety.

CONCLUSIONS

Cere treatment was well tolerated and resulted in significant improvements in the global score two months after the end of active treatment.

Antiapoptotic effects of the peptidergic drug cerebrolysin on primary cultures of embryonic chick cortical neurons

Cerebrolysin (EBEWE Arzneimittel, Austria, Europe) is a widely used drug relieving the symptoms of a variety of neurological disorders, particularly of neurodegenerative dementia of the Alzheimer's type. It consists of approximately 25% of low molecular weight peptides (<10k DA) and a mixture of approximately 75% free amino acids, this being based on the total nitrogen content. In this study we used a low serum (2% serum supplement) cell stress in-vitro model to assess drug effectiveness on neuronal viability and programmed cell death (PCD). In this in-vitro model the type of cell death was previously shown to be primarly apoptotic, which was verified by DNA-laddering and TUNEL-staining. For evaluation of neuronal viability a MTT-reduction assay was performed after 4 DIV and 8 DIV and the percentage of apoptotic neurons was determined by bis-benzimide staining of nuclear chromatin. To differentiate between possible effects of the free amino acids and the peptide fraction of Cerebrolysin an artificial amino acid mixture (AA-mix) was used as a control. Cerebrolysin, the AA-mix and 10% foetal calf serum (FCS) caused a similar increase in viability after 4 DIV, whereas the effects of the growth factors BDNF and FGF-2 were less pronounced. After 8 DIV Cerebrolysin, but not the AA-mix, was able to ameliorate neuronal viability, which could reflect a neuro-protective effect or an increased activity of the mitochondrial dehydrogenase measured in a MTT-reduction assay. The percentage of cells showing apoptotic chromatin changes was significantly reduced (p < 0.01) in cultures treated with Cerebrolysin, whereas the AA-mix failed to decrease the percentage of cells showing apoptotic chromatin changes. These findings ascertain an anti-apoptotic effect of the peptide fraction of Cerebrolysin and reveal a transient viability promoting effect of the amino acid fraction, which is most likely due to improved nutritional supply.

Effects of Cerebrolysin on the outgrowth and protection of processes of cultured brain neurons

Cerebrolysin (Cere, EBEWE Arzneimittel, Austria), a peptidergic drug produced by a standardised enzymatic breakdown of porcine brain proteins, consists of a mixture of 75% free amino acids and 25% low molecular weight peptides (<10 k DA). Cerebrolysin was shown to protect against MAP2 loss in primary embryonic chick neuronal cultures after brief histotoxic hypoxia and in a rat model of acute brain ischemia. Since MAP2 is involved in processes like neuronal growth, plasticity and dendritic branching, we address the question whether Cere is protecting processes against degeneration in a chronic low serum (2% FCS) cell stress model and whether the spontaneous outgrowth of axon-like processes is influenced. This was accomplished by quantification of the neurite lengths of embryonic chicken telencephalon neurons after 4 and 8 days. Additionally, time-lapse video microscopy was performed to study a possible influence of Cere on the growth cone behaviour of axon-like processes. To distinguish between effects caused by the peptide fraction and the effects related to free amino acids, we used an artificial amino acid solution (AA-mix). Results demonstrate a process outgrowth promoting effect of the AA-mix and Cere after 4 DIV. After 8 days neuronal network degeneration occurred in the AA-mix treated cultures, whereas Cere treated cultures still presented a well differentiated neuronal network. Dying neurons could release factors possibly impeding neurite outgrowth and Cere was shown to increase the viability of chicken cortical neurons. Neither the addition of BDNF nor serum supplementation (5% and 10% FCS) could protect the neuronal network against degeneration after 8 DIV, although these treatments were shown to ameliorate the viability of chicken telencephalon neurons. This result together with the finding obtained using the artificial amino acid solution points to the peptide fraction of Cere to be responsible for the protection of processes against degeneration. Time-lapse studies of Cere treated cultures revealed a significant decrease of the velocities characterising random growth cone movements, which is thought to be responsible for an increase in the length of axon-like processes after 4 DIV.

[Anatomical and extra-anatomical reconstructions in aorto-iliac occlusive diseases]

PURPOSE

In the case of the aorto-iliac arteries occlusion there are two different operative reconstructive possibilities. As an anatomical reconstruction the open desobliteration of the iliaca arteries, the retrograde half-closed desobliteration or the aorto/ilio-femoral bypasses can be mentioned. As an extraanatomical solution ilio/femoro-femoral crossover bypass can be implanted. We compared the results of these two types of operations.

PROCEDURE

Between 1 January 1998 and 31 December 1999 at the Cardiovascular Surgical Department of the Semmelweis University Budapest 239 primary, reconstructive operations were done because of the iliac arteries occlusion. We made 175 anatomical and 64 extraanatomical operations. We controlled the results of this operation in this retrospective study.

RESULTS

Since the operation 12 patients died, most of them because of cardial reasons. Hundred sixty seven survival patients could be involved in the study. There was no significant difference regarding the age and the Fontaine stadium of the patients in the two groups. Two-third of the patients underwent anatomical, the others extraanatomical operations. The patency rate in the anatomical group was 92.8%, with the extraanatomical patients 90%. In the view of the postoperative function after the anatomical reconstruction the claudication distance was longer. There were two limb amputations, one of them because of distal progression of the atherosclerosis, in the other case the reason was reocclusion of the graft.

DISCUSSION

In this study we examined patients who underwent an operation about 3 years ago. The preoperative stadium of the two non-selected groups was similar. The postoperative patency rate was quite similar, but the postoperative function after the anatomical reconstruction was significantly better. In our opinion the results of the two different types of the reconstruction used by proper indication were the similarly satisfactory.

[Simultaneous carotid and coronary operations: experience and results of 11 years (1990-2000)]

Between 1990-2000 163 coronary + carotid procedures were performed. The mean age was 4 years higher than it was at patients underwent isolated CABG (63.4 y vs 59.8 y). Clinically proven obliterative artery diseases in other anatomical regions were also present in more than 60% of patients. The half of the procedures were performed under emergency and urgent circumstances. The cardiac status and the coronary morphology were found to be unstable in half of the patients. The "Euroscore" risk evaluation model was used for risk scoring. The mean score value was as high as 6.26. According to this the estimated surgical lethality could have been as high as 11.2%. The real surgical lethality value was far under this estimated level (7.36%). The 1, 5, 10 year survival rate were as high as 89%, 82%, 68% (Kaplan-Meier). The majority of the patients was in NYHA I-II at the end of the follow-up period. The majority of the early and late deaths were found to be myocardial in origin. The estimated surgical risk of the simultaneous procedures could be reduce by accepting of the severe surgical indications existing at this surgical field and with the availability of an experienced operating team.

Increased density of glutamate receptor subunit 1 due to Cerebrolysin treatment: an immunohistochemical study on aged rats

Glutamate receptor subunit 1 (GluR1) is one of the four possible subunits of the AMPA-type glutamate receptor. The integrity of this receptor is crucial for learning processes. However, reductions of GluR1 are noticeable in the hippocampal formation of patients suffering from Alzheimer's disease. Such degradations presumably result in an impaired synaptic communication and might be causally linked to the neurodegenerative process in this cognitive disorder. The peptidergic drug Cerebrolysin counteracts cognitive deficits of patients affected by Alzheimer's disease. These findings are supported by experiments revealing neuroprotective and neurotrophic capacities of the drug. In order to examine the effect of the drug on the density of GluR1 in hippocampal formation 24-month-old rats were treated with either Cerebrolysin or its peptide fraction E021, or saline as a control. Spatial navigation of the animals was tested in the Morris water maze. Rat brain slices were stained immunohistochemically with a GluR1-specific antibody. GluR1 immunoreactivity was quantified using light microscopy and a computerised image analysis system. Cerebrolysin and E021 increased GluR1 density in most measured regions of the hippocampal formation in a highly significant way. These results correlate with the behavioural outcome, revealing an improvement in learning and memory of these rats after treatment with Cerebrolysin and E021.

A brain derived peptide preparation reduces the translation dependent loss of a cytoskeletal protein in primary cultured chicken neurons

Neuronal cytoskeletal proteins like the microtubule associated protein 2 (MAP2) are objected to pathological proteolysis in case of Alzheimer's disease and brain ischemia. The neurotrophic peptidergic drug Cerebrolysin (EBEWE Arzneimittel, Austria, Europe) is produced by a standardized enzymatic break-down of lipid free porcine brain proteins. Cerebolysin protected MAP2 in primary neuronal cultures after a brief histotoxic hypoxia and in a rat model of acute brain ischemia. Furthermore the drug was shown to inhibit the proteases mu- and m-calpain dose dependently in several cell free protease activity assays. The question if the higher MAP2 levels are due to an alleviation of proteolysis, to a higher synthesis rate or both is addressed in the current investigation: Monitoring the MAP2 content of primary neuronal cell cultures over a period of eight days revealed MAP2 to reach a peak level on day six in vitro followed by a degradation phase. In other experiments the protein synthesis of Cerebrolysin treated and untreated cells was blocked with cycloheximide at that moment when all cells exhibited the same MAP2 content. After the following MAP2 degradation phase--i.e. after eight days in vitro--the MAP2 contents were determined by western blotting. Cerebrolysin treated cells contained more MAP2 than untreated controls proving that the drug protects MAP2 independently from de novo synthesis, although further work is in progress to investigate if the drug supplementary boosts this effect by increasing MAP2 synthesis.

Oral Cerebrolysin enhances brain alpha activity and improves cognitive performance in elderly control subjects

Cerebrolysin is a porcine brain derived peptide preparation with potential neurotrophic activity. The effects of a single oral dose of the Cerebrolysin solution (30 ml) on brain bioelectrical activity and on cognitive performance were investigated in healthy elderly people. A single oral dose of Cerebrolysin induced a progressive increase in relative alpha activity power from 1 to 6 hours after treatment in almost all the brain electrodes in elderly control subjects. As compared with baseline alpha power (45.8+/-9.5%), the increase in relative alpha activity in the left occipital electrode (O1) reached significant values at 1 hour (57.2+/-8.5%; p < 0.05), 3 hours (59.4+/-7.6%; p < 0.05) and 6 hours (63.4+/-9.8%; p < 0.05) after Cerebrolysin administration. Enhancement in relative alpha power was accompanied by a generalized decrease in slow delta activity that was maximum at 6 hours after Cerebrolysin intake. A significant improvement in memory performance, evaluated with items of the ADAS cog, was also found in elderly people taken a single dose of oral Cerebrolysin (6.9+/-1.0 errors at baseline versus 4.9+/-1.0 errors after treatment; p < 0.01). This memory improvement was more evident in recognition (2.8+/-0.6 errors vs. 1.5+/-0.7 errors; p < 0.05) than in recall tasks (4.1+/-0.5 errors versus 3.4+/-0.5 errors; ns). These data indicate that Cerebrolysin potentiates brain alpha activity, reduces slow EEG delta frequencies and improves memory performance in healthy elderly humans, suggesting that this compound activates cerebral mechanisms related to attention and memory processes. According to the present results, it seems that oral Cerebrolysin might be useful for the treatment of memory impairment and brain damage in eldely subjects with or without neurodegenerative disorders.

Sustained improvements in patients with dementia of Alzheimer's type (DAT) 6 months after termination of Cerebrolysin therapy

The present study is an extension of the work of Rüther et al. (1994). 101 patients suffering from DAT were evaluated 6 months after completion of a 4 week (5 days per week) therapy with either 30 ml Cerebrolysin or placebo. The significant and clinically relevant improvements in the global rating (CGI), clinical symptomatology (SCAG), cognitive performance (ZVT-G) as primary efficacy variables, as well as the improvements in the secondary efficacy variables activities of daily living (NAI) and wellbeing (Bf-S), achieved in the Cerebrolysin group after only 4 weeks of active therapy, were maintained to a large extent during the follow-up period. Although there was a moderate tendency in the drug group towards loss of improvement, the differences between baseline and follow-up examination, as well as the differences between the verum and the placebo group, clearly document a sustained improvement in patients treated with Cerebrolysin in the first 4 weeks of the study period. It can be speculated that relatively short treatment courses with Cerebrolysin in patients suffering from neurodegenerative dementia can lead to long term influence on disease progression, which is in accordance with the proposed neurotrophic - nerve growth factor like - mode of action.

Effects of NaCN and ionomycin on neuronal viability and on the abundance of microtubule-associated proteins MAP1, MAP2, and tau in isolated chick cortical neurons

The effects of two toxins, sodium cyanide (NaCN) and ionomycin (IM), on neuronal viability and on the expression of the microtubule-associated proteins MAP1, MAP2, and tau were studied in isolated chick cortical neurons. Cytotoxic hypoxia due to NaCN treatment was performed to mimic acute neuronal damage, whereas long-term IM treatment was used as a model for chronic neuronal impairment. After 5 days in vitro, a cytotoxic lesion was induced either by addition of NaCN (0.01-10 mM) or IM (0.01-10 microM). The NaCN solution was aspirated after 30 min and cells were allowed to regenerate for 6 h, 24 h, 48 h, or 72 h; whereas the permanent IM lesions were left undisturbed during the same periods of time. Neuronal viability was assessed by MTT assay. The abundance of MAP1, MAP2, and tau was evaluated by immunoblotting and, for MAP2, by immunohistochemistry also. Results showed that NaCN and IM lesions dose-dependently decreased viability. Irreversible cell damage occurred after impairment with 10 mM NaCN and 1 microm or 10 microm IM, while neurons lesioned with lower concentrations regenerated partially or adapted to the toxic environment. However, the same level of viability as of untreated cells was never reached. Furthermore abundance of MAPs was changed after both lesions. But while after extended recovery from NaCN lesion protein expression was normalizing (MAP2) or at least still detectable (MAP1A, tau), the consequences of a permanent IM lesion were more severe, since neurons were not able to maintain or even restore their MAP expression. Immunohistochemical experiments for MAP2 revealed that, compared with controls, NaCN and, to a much higher extent, IM treatment resulted in a loss of immunoreactivity in neurites due to progressing cell death.

Inhibitory effect of a brain derived peptide preparation on the Ca++-dependent protease, calpain

Overactivated calpain might be a key factor in destruction of cytoskeletal proteins involved in the pathophysiology of ischemia and disorders like Alzheimer's disease. Therapeutic effects imply the possible interference of Cerebrolysin (Ebewe Arzneimittel, Austria) with these molecular events. In this work several in vitro methods have been applied to investigate the interaction between Cerebrolysin and calpain [Enzyme Commission (EC) number: 3.4.22.17]. A conventional caseinolytic assay beside two flourimetric assays using a synthetic peptide substrate and a fluorescence labelled cytoskeletal protein [microtubule-associated protein 2 labelled with 5-([4,6-dichlorotriazin-2-yl]amino) fluorescein (MAP2-DTAF)] respectively for a highly sensitive fluorimetric calpain activity assay were applied for kinetic analysis. The caseinolytic assay showed that the drug inhibits both mu- and m-calpain and to a significantly lower extent also trypsin [Enzyme Commission (EC) number: 3.4.21.1] and papain [Enzyme commission (EC) number: 3.4.22.6]. Dialysis experiments revealed Cerebrolysin mediated calpain inhibition to be reversible. Kinetic analysis exhibited a non-competitive, or tight-binding competitive, mode of inhibition. This latter mode, substantiated by serial dilution experiments, and the likely existence of calpastatin in a brain derivative suggests the occurrence of calpastatin fragments or calpastatin-like fragments in Cerebrolysin. The clearly competitive inhibition of trypsin by the drug indicates distinct mechanisms and active components against different proteases.

Pharmacological treatment of Alzheimer disease: from psychotropic drugs and cholinesterase inhibitors to pharmacogenomics

For the past 20 years the scientific community and the pharmaceutical industry have been searching for treatments to neutralize the devastating effects of Alzheimer disease (AD). During this period important changes in the etiopathogenic concept of AD have occurred and, as a consequence, the pharmacological approach for treating AD has also changed. During the past 2 decades only 3 drugs for AD have been formally approved by the FDA, although in many countries there are several drugs which are currently used as neuroprotecting agents in dementia alone or in combination with cholinesterase inhibitors. The interest of the pharmaceutical industry has also shifted from the cholinergic hypothesis which led to the development of cholinesterase inhibitors to enhance the bioavailability of acetylcholine at the synaptic cleft to a more "molecular approach" based on new data on the pathogenic events underlying neurodegeneration in AD. In our opinion, the pharmacological treatment of AD should rely on a better understanding of AD etiopathogenesis in order to use current drugs that protect the AD brain against deleterious events and/or to develop new drugs specifically designed to inhibit and/or regulate those factors responsible for premature neuronal death in AD. The most relevant pathogenic events in AD can be classified into main categories: primary events (genetic factors, neuronal apoptosis), secondary events (beta-amyloid deposition in senile plaques and brain vessels, neurofibrillary tangles due to hyperphosphorylation of tau proteins, synaptic loss), tertiary events (neurotransmitter deficits, neurotrophic alterations, neuroimmune dysfunction, neuroinflammatory reactions) and quaternary events (excitotoxic reactions, calcium homeostasis miscarriage, free radical formation, primary and/or reactive cerebrovascular dysfunction). All of these pathogenic events are potential targets for treatment in AD. Potential therapeutic strategies for AD treatment include palliative treatment with nonspecific neuroprotecting agents, symptomatic treatment with psychotropic drugs for noncognitive symptoms, cognitive treatment with cognition enhancers, substitutive treatment with cholinergic enhancers to improve memory deficits, multifactorial treatment using several drugs in combination and etiopathogenic treatment designed to regulate molecular factors potentially associated with AD pathogenesis. This review discusses the conventional cholinergic enhancers (cholinesterase inhibitors, muscarinic agonists), noncholinergic strategies that have been developed with other compounds, novel combination drug strategies and future trends in drug development for AD treatment. Stem-cell activation, genetically manipulated cell transplantation, gene therapy and antisense oligonucleotide technology constitute novel approaches for the treatment of gene-related brain damage and neuroregeneration. The identification of an increasing number of genes associated with neuronal dysfunction along the human genome together with the influence of specific allelic associations and polymorphisms indicate that pharmacogenomics will become a preferential procedure for drug development in polygenic complex disorders. Furthermore, genetic screening of the population at risk will help to identify candidates for prevention among first-degree relatives in families with transgenerational dementia.

[New method for the intraoperative biochemical monitoring of cerebrospinal fluid in surgery of thoracoabdominal aortic aneurysms]

Paraplegia remains to be one of the most dangerous complications following thoracoabdominal aortic surgery with an incidence of 0.5 to 40%. Therefore, intraoperative monitoring of spinal cord function is very important when choosing the appropriate surgical technique. Early detection of spinal cord injury continues to be a crucial problem, moreover, the currently applied electrophysiological methods appear to be inaccurate. The aim of the study was to detect prospective spinal cord injury intraoperatively by monitoring the biochemical parameters of the cerebrospinal fluid (CSF). The authors studied the reversible aerobic/anaerobic metabolic changes by monitoring CSF lactate levels, moreover S-100 protein and neuron-specific enolase (NSE) concentrations--specific for neuroglia and neuronal injury, respectively. One of the important methods to prevent paraplegia is the intraoperative CSF drainage, which may improve spinal cord perfusion. Between 1996-1998 51 patients underwent reconstructive thoracic or thoracoabdominal aortic aneurysm operation. The continuously drained CSF was collected in 10 ml fractions during the preparation, whereas during aortic cross-clamping and de-clamping 10 minute fractions were used. All CSF samples were immediately analysed intraoperatively for pH, pCO2, HCO3, potassium and lactate levels, S-100 protein and NSE were analysed by immunoluminescence. CSF lactate levels increased slightly during aortic clamping and a moderate, but non-significant increase was found in the hyperemic phase (reperfusion) in patients without spinal cord ischemia. Spinal cord injury was detected in 7 cases. These patients exhibited a significant CSF-lactate increase (control vs aortic cross-clamping: 1.9 vs 5.3 mmol/l), moreover CSF-lactate remained elevated throughout the whole operation. Paraplegia did not occur, Tarlov 2 paraparesis developed in four cases and three patients displayed cerebral damage. Intraoperative CSF--especially CSF-lactate--monitoring may help the operating team to detect early anaerobic changes of the metabolism the spinal cord.

Two peptidergic drugs increase the synaptophysin immunoreactivity in brains of 6-week-old rats

An increase of synaptic density has been found in the hippocampus, the dendate gyrus and in the entorhinal cortex of 6-week-old rats after 7 days of treatment with the peptidergic drug Cerebrolysin, its peptide preparation E021 and the diluted peptide preparation E021dil. Rats received drugs on postnatal days 1-7 (2.5 ml/kg, each day). Controls received saline. The animals were sacrificed on days 42-48 of their life, after they had undergone behavioural testing in a Morris water maze. Slices of brain were stained immunohistochemically with anti-synaptophysin, a specific marker of presynaptic terminals. The synaptophysin-immunoreactivity of presynaptic terminals was quantified using light microscopy and a computerised image analysis system. Our results showed that rats benefit from the treatment with both drugs. A significant increase in the number of synaptophysin-immunoreactive presynaptic terminals was found in the entorhinal cortex and the hippocampal subfields CA1, CA2, CA3 stratum radiatum and CA3 stratum lucidum. The increased immunoreactive presynaptic terminals found in the present study are in accordance with the positive effects of the drugs on spatial learning and memory in young rats (Gschanes & Windisch 1999).

The drug cerebrolysin and its peptide fraction E021 increase the abundance of the blood-brain barrier GLUT1 glucose transporter in brains of young and old rats

The brain-derived peptidergic drug Cerebrolysin has been found to support the survival of neurons in vitro and in vivo. In the present study, we investigated the effects of Cerebrolysin and its peptide preparation E021 on spatial learning and memory, as well as on the abundance of the blood-brain barrier GLUT1 glucose transporter (GLUT1) in 2-month-old and 24-month-old rats. Young rats were treated with the drugs or saline (2.5 ml/kg/day) daily on postnatal days 1-7, and old rats for 19 consecutive days. For behavioural testing the Morris water maze was used. The abundance of GLUT1 was determined in brain slices by immunocytochemistry. Quantification of the density of the GLUT1 immunostaining was performed using light microscopy and a computerised image analysing system. All drug-treated rats, young and old, exhibit shorter escape latencies in the water maze, on all testing days (p < 0.01), indicating improved cognitive performance. Immunohistochemical data show an age-related decrease of the density of GLUTI (p < 0.05). In young animals, the administration of the drugs led to an increase of the abundance of GLUT1 in all experimental groups (p < 0.01). In old rats, the treatment with Cerebrolysin, but not with E021, resulted in an increase in the immunoreactive GLUT1 (p < 0.01). The elevated abundance of GLUT1 after the administration of both peptidergic substances might be supportive for the cognitive effects of this drug, by causing an improved nutritional supply of glucose to the neurons.

Cerebrolysin reduces microglial activation in vivo and in vitro: a potential mechanism of neuroprotection

Neurotrophins, such as NGF, BDNF and NT-3 play a regulatory role on the function of microglial cells in vivo and in vitro, and the identification of new compounds with neurotrophic properties is becoming a new strategy for the prevention and/or treatment of neurodegenerative disorders. In this study we describe the use of two different models to demonstrate the ability of Cerebrolysin to reduce microglial activation. The results of these in vitro and in vivo studies indicate that Cerebrolysin might exert a neuroimmunotrophic activity reducing the extent of inflammation and accelerated neuronal death under pathological conditions such as those observed in neurodegenerative diseases.

Approach towards an integrative drug treatment of Alzheimer's disease

At present pharmacotherapy of Alzheimer's disease (AD) is limited to acetylcholinesterase inhibitors. These drugs produce small, but consistent improvements of memory and global function, some are also positively influencing activities of daily living. This therapeutic approach neglects the complexity of AD and the fact that most of the degenerating neurons are not cholinergic. Acetylcholinesterase inhibitors are symptomatic drugs, with no influence on disease progression. There is a need for disease modifying compounds, or preventive drugs. Data are indicating that vitamin E has some ability to influence the disease progression. The potency of non-steroidal anti-inflammatory drugs (NSAIDs) or estrogen as preventive agents has to be explored further in prospective clinical studies. The initial hope in the use of naturally occurring neurotrophic factors, like nerve growth factor, to rescue cholinergic neurons from degeneration and to restore cognitive function has been disappointed in first, small clinical studies. The peptidergic drug Cerebrolysin exhibiting neurotrophic stimulation, neuroimmunotrophic regulation and induction of BBB glucose transporter expression, might be able to address the pathological changes of AD at different levels simultaneously. In addition to an impressive preclinical database, results from 3 placebo-controlled, double-blind studies demonstrate significant improvements of cognitive performance, global function and activities of daily living in AD patients. In all studies persisting improvements, up to 6 months after drug withdrawal, indicate a powerful disease modifying activity.

In vivo upregulation of the blood-brain barrier GLUT1 glucose transporter by brain-derived peptides

Glucose is the critical metabolic fluid for the brain, and the transport of this nutrient from blood to brain is limited by the blood-brain barrier (BBB) GLUT1 glucose transporter. The expression of the BBB-GLUT1 gene is augmented in brain endothelial cultured cells incubated with brain-derived trophic factors and the brain-derived peptide preparation Cerebrolysin (C1, EBEWE, Austria). The aim of the present investigation was to determine if C1 induces similar changes in the expression of the BBB-GLUT1 gene following its administration to rats in vivo. The BBB glucose transporter activity was investigated with the intracarotid artery perfusion technique using [3H]diazepam as cerebral blood flow marker. The acute or chronic administration of C1 markedly increased the brain permeability surface area of D-[14C]glucose compared to controls (D-[14C]glucose/[3H]diazepam ratio, 1.6- to 1.9-fold increase in frontal cortex, P < 0.05). Increased activity of the BBB glucose transporter was correlated with a significant rise in the abundance of the BBB-GLUT1 protein measured by both Western blot analysis and immunocytochemistry, and with a decrease in the transcript levels of this transporter. Data presented here demonstrate that the in vivo administration of Cl increases the transport of glucose from blood to brain via BBB-GLUT1 gene expression.

Two peptidergic drugs increase the synaptophysin immunoreactivity in brains of 24-month-old rats

The brain-derived peptidergic drug Cerebrolysin has been found to support the survival of neurones in vitro and in vivo. Positive effects on learning and memory have been demonstrated in various animal models and also in clinical trails. In the present study, the effects of Cerebrolysin and its peptide preparation E021 on the synapse density in the hippocampus, the dentate gyrus and in the entorhinal cortex of 24-month-old rats were investigated. Rats received the drugs or saline for control for 19 consecutive days (2.5 ml/kg per day). Slices of the brains were immunohistochemically stained with anti-synaptophysin, which is a specific marker of presynaptic terminals. Quantification of the synapse density was done by using light microscopy and a computerised image analysing system. Our results clearly showed that the rats benefit from the administration of both drugs, showing an enhancement in the number of synaptophysin-immunostained presynaptic terminals in the entorhinal cortex, the dentate gyrus, and also in the hippocampal subfields CA1, CA2, CA3 stratum lucidum and CA3 stratum radiatum. It can be assumed that these effects are the reason for improved cognitive performances of rats treated with Cerebrolysin and E021.

Effects of Cerebrolysin on in vitro primary microglial and astrocyte rat cell cultures

In recent years the potential use of neurotrophic factors in the prevention and/or treatment of neurodegenerative diseases has received much attention. To determine whether Cerebrolysin, a porcine brain-derived peptide preparation, was able to modulate in vitro lipopolysaccharide (LPS)-induced microglial activation and to test the direct effect of Cerebrolysin on astrocyte morphology, survival and proliferation, rat glial and astrocyte cell culture experiments were carried out. The morphology of microglia, ameboid/activated and flat/resting, was examined under contrast microscopy and cell counts obtained. In addition, the release of interleukin (IL)-1 beta and brain-derived neurotrophic factor (BDNF) was measured from cell culture supernatant using an enzyme-linked-immunoassay (ELISA). The results obtained in this study clearly suggest a protective effect of Cerebrolysin as revealed by downregulation of microglial activation after LPS treatment as well as by the control of IL-1 beta expression. No significant differences were observed on astrocyte morphology, survival or the production and/or release of BDNF. In conclusion, these in vitro studies indicate that Cerebrolysin might exert a neuroimmunotrophic function which can in turn reduce the extent of inflammation and accelerate neuronal death under pathological conditions such as human neurodegenerative disorders.

Early postnatal treatment with peptide preparations influences spatial navigation of young and adult rats

The brain derived peptidergic drug Cerebrolysin has been found to support the survival of neurons in vitro and in vivo. Positive effects on learning and memory have been demonstrated in various animal models and also in clinical trials. In the present study the effects of early postnatal administration of Cerebrolysin (Cere, 10 mg/ml peptides) or an enriched peptide fraction of Cere (E021, 80.6 mg/ml peptides) were investigated in young, young adult, and old adult rats. Rat pups received the drugs or saline for control on postnatal days 1-7. The animals were tested in the Morris water maze (MWM) either in the 5th week, in the 3rd or the 16th month of life for 6 consecutive days (test days 1-6), eight trials per day. In order to prevent the chance finding of the hidden platform, the rigid underwater platform was replaced by a collapsible island, resting at the bottom of the pool. The platform was raised when the animal stayed in the target area for 2 s. In the young and young adult rats both Cere and E021 treated rats showed shorter escape latencies than saline treated controls on all 6 test days. No significant differences in the swimming speed were evaluated for the young rats, although in 3-month-old drug-tested animals a moderate increase of the swimming speed was investigated. For 16-month-old animals no significant differences in either escape latencies or swimming speed was found. Summarizing, early postnatal application of Cere or E021 improved the spatial learning and memory of young rats and led to long-lasting behavioural effects at least up to 3 months after treatment.

Neurotrophic activities and therapeutic experience with a brain derived peptide preparation

In spite that the use of naturally occurring neurotrophic factors like NGF, BDNF, CNTF, GDNF and others for treatment of neurodegenerative disorders seems promising because of their pharmacological properties, until now no large scale clinical trials have been published. One of the reasons is that these molecules are unable to penetrate through the blood brain barrier, making invasive application strategies like intracerebroventricular infusion necessary. Another one is the fact that in first clinical studies, several undesirable side-effects like hyperalgesia or weight loss have been reported. Major efforts are now put into development of improved application procedures and in treatment protocols for avoiding the known side-effects. Already 7 years ago it has been demonstrated that Cerebrolysin, a peptidergic drug, produced from purified brain proteins by standardized enzymatic breakdown, containing biologically active peptides, is exerting nerve growth factor like activity on neurons from dorsal root ganglia. Still ongoing investigations are showing growth promoting efficacy of this drug in different neuronal populations from peripheral and central nervous system. The current findings are in accordance with several older publications, enabling now a more clear interpretation of these findings. In addition to the direct neurotrophic effect, the drug also shows clear neuroprotective properties after different types of lesion in vitro and in vivo, resembling the pharmacological activities of naturally occurring nerve growth factors. Neurotrophic and neuroprotective efficacy has been shown with a broad variety of methods in different models and it is remarkable that all biochemical and morphological drug dependent alterations are resulting in improvements of learning and memory. Because of these experimental results, clinical trials using cerebrolysin in Alzheimer's patients have been performed, demonstrating a quick improvement in the overall state of the patients, particularly enhancing the cognitive performance. It is remarkable that these effects are long lasting after cessation of the active treatment procedure. Even 6 months after stop of drug application improvements in AD-patients are detectable. Therefore it is concluded that cerebrolysin is able to induce repair phenomena, resulting in long term stabilization. In contrast to the naturally occurring growth factors, tolerability of this drug is extremely high, without any reports about serious side-effects in these clinical studies.

Cerebrolysin protects isolated cortical neurons from neurodegeneration after brief histotoxic hypoxia

A brief period of histotoxic hypoxia exhibits certain metabolic features resembling the in vivo situation of ischemia. In this study the neuroprotective effects of the peptidergic nootropic drug Cerebrolysin (Cere) against iodoacetate induced histotoxic hypoxia were investigated. For that purpose isolated cortical neurons from 9 day chicken embryos were precultured with 0 to 6.4 mg.Cere/ml medium. At the 8th day in vitro histotoxic hypoxia was induced by incubation with 0.01 or 0.1 mM iodoacetate. Cells were allowed to recover from toxic stress for 3, 6, 24 or 48 hours. Cere protected neurons dose dependently from delayed neuronal cell death due to 0.01 mM iodoacetate even after a recovery period of 48h. After induction of histotoxic hypoxia by 0.1 mM iodoacetate high concentrations of Cere again led to neuronal protection after the 3 and 6 h recovery period. Moreover the influence of Cere on the cytoskeletal protein MAP2 in neurons submitted to 0.01 mM iodoacetate was investigated. With Western blotting and immunohistochemical techniques it has been demonstrated that the drug clearly increased MAP2 abundance after histotoxic hypoxia. The present study points out that after severe damage of cortical neurons with iodoacetate Cere is able to protect neurons from delayed neuronal cell death maybe by maintaining neuronal plasticity due to avoidance of the cytoskeletal breakdown.

Further evidence that Cerebrolysin protects cortical neurons from neurodegeneration in vitro

The effects of Cerebrolysin on isolated chicken cortical neurons in an iron induced oxidative stress model and in a combined iron-glutamate model have been examined. In a first part of experiments it has been shown that under low serum conditions exposure of neurons to different concentrations of ammonium-iron (III)citrate (1, 5 microM AC-Fe3+) for 8 days caused a significant reduction in neuronal survival. Cerebrolysin not only prevented iron induced neurodegeneration, demonstrating that ionic iron was responsible for the cell damage, moreover, it increased the neuronal viability up to tenfold with respect to the controls. In the second part of the study neurons pre-incubated for 8 days with AC-Fe3+ were additionally lesioned with 1 mM L-glutamate and allowed to recover for another 48 h. Under these conditions cerebrolysin again clearly counteracted the in vitro destructive effects of glutamate. Besides consequences on the viability and survival of neurons Cerebrolysin increased abundance of the microtubule-associated protein MAP2, which is known to play a an important role in maintaining normal neuronal function.