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Biomedical subjects

N Müller

Publications and source records attributed to N Müller.

At least 37 records · Page 2Linked to original sources
PubMed2005

Association of multiple sclerosis with ILT6 deficiency.

Multiple sclerosis (MS) is an autoimmune disorder of multifactorial etiology. Family studies have shown strong genetic contributions. Linkage analyses have revealed several regions harboring risk genes including chromosome region 19q13. ILT6 is one of the most interesting candidate genes, since ILTs are involved in the generation of immunological tolerance. There is an absence/presence of variability of the ILT6 gene comprising several exons, thus incapacitating the gene function. In the present study, we examined the association of ILT6 deletion with MS. Using PCR typing, deficiency of ILT6 was examined in 607 blood donors and in 751 Caucasian German, as well as 89 French MS patients. Homozygous ILT6 deficiencies were significantly more prevalent in MS patients (7.1%) than in blood donors (3.8%; P=0.009). ILT6 deficiency is associated with MS in the German population and hence a likely risk factor for autoimmune disorders.

Chromosomes, Human, Pair 19↗
PubMed2005

Cutaneous leishmaniasis in naturally infected dogs is associated with a T helper-2-biased immune response.

Skin lesions are a frequent manifestation of Leishmania infantum infections in Mediterranean countries. This study demonstrates by real-time reverse transcriptase-polymerase chain reaction the local cytokine response in skin biopsies from Leishmania-infected dogs (n=10). As controls, we investigated skin biopsies from healthy (n=10) and fleabite hypersensitive dogs (n=10). We established a quantitative PCR to determine the parasite burden in biopsies. The objective was to elucidate whether a correlation exists between parasite number, histologic response, and T helper-1 (TH1)/T helper-2 (TH2) cytokine expression in lesional skin of naturally infected dogs. In Leishmania-infected dogs, interleukin-4 (IL-4), tumor necrosis factor alpha (TNF-alpha) and interferon-gamma (IFN-gamma) messenger RNA production was significantly higher than controls. Furthermore, dogs with a high Leishmania burden had a significantly higher IL-4 expression, whereas no difference was noted with regard to expression of other cytokines. By comparing the pattern of inflammation and cytokine expression, a clear trend became evident in that levels of IL-4, TNF-alpha, and IFN-gamma were elevated in biopsies with a periadnexal nodular pattern and in biopsies where the severity of the periadnexal infiltrate was equal to the perivascular to interstitial infiltrate. Expression of IL-4, IL-13, and TNF-alpha was slightly increased in biopsies where plasma cells prevailed on lymphocytes, whereas expression of IFN-gamma was moderately higher when lymphocytes were predominating. In summary, the present study demonstrates that the local immune response in naturally occurring leishmaniasis includes TH1 as well as TH2 cytokine subsets. Furthermore, respective data suggest that increased expression of the TH2-type cytokine IL-4 is associated with both severe clinical signs and a high parasite burden in the skin lesions.

Animals↗
PubMed2004

An interlaboratory comparison of immunohistochemistry and PCR methods for detection of Neospora caninum in bovine foetal tissues.

Seven European laboratories contributed to a multi-centre evaluation of detection techniques for Neospora caninum in bovine foetuses. Six laboratories participated in immunohistochemistry (IHC) testing. All seven laboratories participated in PCR testing, but the results from one laboratory were not included in the analysis, because of contamination problems in the preparation of the samples. A coded panel of tissue sections from 36 infected and non-infected foetuses was used to evaluate the IHC detection of parasites. A coded panel consisting of 44 homogenized foetal brain samples from natural bovine abortion cases and 32 spiked samples were used to evaluate the PCR methods. Inclusion of a duplicate dilution series of spiked samples was used to evaluate detection limits and repeatability. IHC methods had a relatively low sensitivity, but a high specificity. There was considerable variation in IHC results between participating laboratories, which may be partly explained by examination practices that depended on the experience of the operator. In addition, the use of different antibody reagents, different antibody dilutions, and different enzymatic treatments of tissues may have contributed to the observed variation. PCR methods generally had a higher sensitivity than IHC methods and also a high specificity. The agreement between the majority scores of IHC and PCR methods was low. False positive PCR results indicated contamination problems in some instances. Agreement between the PCR results of the various laboratories was better, compared with the IHC results. There appeared to be no clear relationship between the PCR format (i.e. single or nested) and diagnostic sensitivity. Consequently, an improvement of diagnostic performance of PCR might possibly be achieved by optimizing DNA extraction methods.

Abortion, Veterinary↗
PubMed2004

Risperidone plasma levels, clinical response and side-effects.

INTRODUCTION: Assessment of the relation between oral risperidone dose, serum drug levels and clinical response may provide important information for rational treatment decisions. Inter-individual differences in the liver cytochrome P450 system, especially in the CYP2D6 subsystem, which account for a significant portion of risperidone metabolism, may also influence plasma drug levels and alter clinical response parameters. We thus prospectively investigated risperidone serum concentrations in relation to clinical efficacy and side-effects and genotyped major CYP2D6 polymorphisms to determine their effect upon these parameters. METHODS: Neuroleptic monotherapy with risperidone was administered to schizophrenia patients in a 6-week open dose clinical trial. Weekly assessments including CGI and PANSS ratings to assess psychopathology; SAS to assess medication side effects; and blood draws to quantify steady state plasma levels of risperidone and 9-OH-risperidone were carried out. In addition, major CYP2D6 polymorphisms including alleles *4, *6 and *14 were genotyped. RESULTS: Eighty-two patients were recruited. Mean oral dose of risperidone was 4.3 +/- 0.9 mg. Mean plasma level of both risperidone and 9-OH-risperidone together ("active moiety") was 41.6 +/- 26.6 ng/ml. Significant improvements in PANSS scales and the various subscales ensued. There was a positive linear correlation between active moiety plasma levels and dose (r = 0.291, p = 0.015) and between risperidone and 9-OH-risperidone levels (r = 0.262; p = 0.016). Nonresponders to pharmacotherapy (PANSS-Improvement < 30%) showed significantly higher active moiety plasma levels (49.9 +/- 30.7 ng/ml) than responders (38.2 +/- 17.0 ng/ml; p = 0.045) without significantly higher oral doses (p = 0.601). Patients with longer illness duration (> or = 3 years) had significantly higher plasma drug levels than those with a shorter course (< 3 years; p = 0.039). Extrapyramidal side effects (EPS) and plasma levels were not correlated (r = 0.028; p = 0.843), but higher plasma levels at week 2 predicted an incidence for EPS (p < 0.050). Accordingly, patients initially receiving higher oral doses of risperidone were significantly more likely to respond with EPS in the trial course. Eight patients (9.8%) were heterozygous carriers of the CYP2D6 allele *4. CYP2D6 polymorphisms did not predict clinical response, but predicted a tendential increase in the plasma risperidone to 9-OH-risperidone ratio (0.5 +/- 0.6 vs. 1.9 +/- 1.8; p = 0.120). DISCUSSION: The major finding was that responders to risperidone treatment had significantly lower blood levels of risperidone and 9-OH risperidone than patients who did not respond to the treatment despite administration of similar oral doses. The observed CYP2D6 polymorphisms did not contribute to altered clinical efficacy, but affected risperidone to 9-OH-risperidone ratios. Increased plasma levels of the active moiety in patients with longer illness may represent general aging effects. Conversely, the observed higher plasma levels in nonresponders may derive from unaccounted genetic metabolism abnormalities or Phase II metabolism disturbances. Patients initially receiving higher oral risperidone doses were more likely to respond with extrapyramidal side effects which reaffirms the need for careful titration. The high inter-individual variability in risperidone and 9-OH-risperidone metabolization and the relationship between clinical outcome and plasma levels warrants regular plasma level monitoring of both compounds to assess for the clinically relevant active moiety.

Adolescent↗
PubMed2004

How representative of everyday clinical populations are schizophrenia patients enrolled in clinical trials?

INTRODUCTION: There has been considerable discussion whether clinical trials accurately depict everyday practice. Restrictive inclusion/exclusion criteria, ethical considerations, differences in the severity of psychopathology between clinical and trial patients, or safety issues may bias results, which in turn may rather represent outcome for the "ideal" than for the "average"patient. Therefore, translation into psychiatric practice may be difficult. METHODS: A retrospective case-control study was performed. Schizophrenia inpatients at the LMU Department of Psychiatry, Munich, Germany, who had participated in clinical trials were compared to regular patients serving as controls. Probands and controls were matched by DSM-IV diagnosis, gender and age. The AMDP module, CGI and GAF were used to compare psychopathology. In addition, charts were reviewed for medication dosages, concurrent medical and neurological illness, and clinical history such as age of onset or family history. RESULTS: A total of 200 probands (100/100) were enrolled in the study. With respect to psychopathology, formally thought disordered or suicidal patients were significantly less likely to be study participants (n = 3) than controls (n = 22; p < or = 0.05). Similarly, negative schizophrenia symptoms were significantly less often present in study participants (n = 17) than in controls (n = 38; p < or = 0.05). Study participants were also medically and neurologically healthier than controls. (p = 0.05 respectively). No differences in overall illness severity as depicted by CGI and GAF were observed. CONCLUSION: We found the patients included in our clinical trials representative of the patient encountered in routine clinical practice. Adherence to inclusion and exclusion criteria prevents inclusion of severely ill (e. g. suicidal) patients requiring a more intensive treatment setting. Illness severity was found to be similar in trial participants and controls, and indicates an overall comparably severe psychopathology. The more chronic, rather treatment refractory patients were also not reflected in the trial participant pool; this population may arguably not represent the average clinical patient either. A more careful administration of antipsychotic medication was found in trial participants and may effectively be considered "good clinical practice".

Adult↗
PubMed2004

Characterisation of Trichinella isolates from Bulgaria by molecular typing and cross-breeding.

Trichinella spp. larvae were collected from domestic and wild-life animals in association with 15 human trichinellosis outbreaks registered between 1999-2002 in Bulgaria. Furthermore, Trichinella spp. isolates were obtained from 62 naturally infected wild animals and of a rat. All isolates were subjected to speciation by both multiplex PCR and cross-breeding experiments. Epidemiological and clinical data were collected and analysed using standard protocols for epidemiological surveillance and control of outbreaks. Only two species were identified-Trichinella britovi and Trichinella spiralis. Results obtained by molecular typing fully matched those of cross-breeding. More specifically, parasite isolates obtained upon 15 epidemic outbreaks revealed the predominance of T. britovi (n = 10) when compared to T. spiralis (n = 5). With regard to host origin, the predominant species detected among wild boar was T. britovi (n = 4), and T. spiralis was identified in one wild boar sample only. Among the isolates obtained from domestic pig products, T. britovi was found in five cases and T. spiralis in four cases, respectively. In the naturally infected wild animals not related to epidemics, only T. britovi was demonstrated. The present results provide a strong indication that both T. britovi and T. spiralis operate within domestic and sylvatic cycles in Bulgaria. Geographically, the distribution of T. britovi appears to include Central, Southern, Eastern and Western parts of the country, and wildlife animals from the Mid Balkan Mountains and Mid Sredna Gora Mountains, T. spiralis was found in Western and Southwestern Bulgaria, only.

Animals↗
PubMed2004

The fuzzy frontier between subjective memory complaints and early dementia. A survey of patient management in German memory clinics.

BACKGROUND: Mild cognitive decline is frequent in the elderly population. Whether it is related to normal aging or an early phase of evolving dementia is difficult to ascertain with confidence, and accordingly there is a lack of consensus guidelines for diagnosis and therapy in such patients. We assessed the variability with which memory clinics deal with this problem in everyday practice. METHODS: We sent three fictitious case histories to all 85 German memory clinics that contained the results of clinical examination and neuropsychological test scores and asked for diagnosis and patient management. Patient 1 presented with complaints of mental decline but normal neuropsychological and neurological evaluation and normal daily living activities. Patient 2 came in as a control subject for a study and had impaired test scores but preserved daily living activities, and patient 3 was brought in by relatives with slight impairment of daily living activities and decline in some neuropsychological test scores but relatively spared memory scores. RESULTS: Most of the 51 respondents agreed in recommending further neuropsychological testing, a basic laboratory work-up, brain imaging, and a re-examination after 3-6 months. Yet, there was a high variability in the diagnostic terms used, in the additional diagnostic procedures proposed, and in the recommendations concerning therapeutic intervention and driving. CONCLUSIONS: The results reveal a need of practice guidelines for the use of diagnostic terms, therapeutic interventions and driving recommendations in patients between subjective memory complaints and early dementia.

Activities of Daily Living↗
PubMed2004

Training and education--with a view of the involvement in Germany.

The replies of 15 countries to the questionnaires-training and education-have shown that transfusion medicine teaching and education regarded as a definitely clearly defined specialty with different tones and degrees, is to be considered at different levels relating to teaching basic knowledge of transfusion medicine during the education as well as in the postgraduate training. The reported results may serve as an incentive or impulse to suitable regulations and a common consensus of transfusion medicine curriculum although each European Country has its peculiarities.

Blood Transfusion↗
PubMed2004

Cloning and sequencing of a cDNA expressing a ribosomal P0 peptide from Culicoides nubeculosus (Diptera).

Insect bite dermal hypersensitivity (IBH) is an allergic dermatitis of horses caused by bites of Culicoides spp. and sometimes Simulium spp. The aim of the investigation presented here was to identify allergens causing IBH. A cDNA library expressing recombinant Culicoides nubeculosus proteins was screened using affinity-purified serum from an IBH-affected horse. Screening of the library resulted in identification of one immunoreactive clone. The sequence of the cDNA insert was determined and revealed a 600 bp insert with an open reading frame coding for a 78 amino acid long protein, called rCul n 1. Analysis of the deduced amino acid sequence revealed an identity of 67-78% to the C-terminal part of the 318 amino acid long ribosomal P0 protein from other Diptera. Furthermore, the 38 C-terminal amino acids displayed an identity of 57% with the C-terminal part of the acidic ribosomal protein P2 from Aspergillus fumigatus. The cDNA insert was subcloned and expressed as a [His]6-tagged protein in Escherichia coli and purified using Ni2(+)-chelate affinity chromatography. The 10kDa recombinant Cul n 1 protein bound the affinity-purified antibody fraction used for screening the expression library. Determination of IgE and IgG levels against rCul n 1 by ELISA in sera from 19 IBH-affected and 18 Swiss control horses and in sera from eight control horses living in Iceland showed no significant differences between the three groups of horses (median IgE levels = 60, 49 and 44 relative ELISA units, respectively). rCul n 1 did not induce sulfidoleukotriene (sLT) release from peripheral blood leukocytes of IBH-affected horses (N = 5), although sLT release was induced with the Culicoides whole body extract.

Allergens↗
PubMed2004

Prevalence, co-morbidity and correlates of mental disorders in the general population: results from the German Health Interview and Examination Survey (GHS).

BACKGROUND: The German National Health Interview and Examination Survey (GHS) is the first government mandated nationwide study to investigate jointly the prevalence of somatic and mental disorders within one study in the general adult population in Germany. This paper reports results from its Mental Health Supplement (GHS-MHS) on 4-week 12-month, and selected lifetime prevalence of a broad range of DSM-IV mental disorders, their co-morbidity and correlates in the community. METHODS: The sample of the GHS-MHS (n=4181; multistage stratified random sample drawn from population registries; conditional response rate: 87.6%) can be regarded as representative for the German population aged 18-65. Diagnoses are based on fully structured computer assisted clinical interviews (M-CIDI), conducted by clinically trained interviewers. RESULTS: 12-month prevalence for any DSM-IV study disorder is 31% (lifetime: 43%; 4-week: 20%) with anxiety disorders, mood disorders and somatoform syndromes being the most frequent diagnoses. Retrospective age of onset information reveals that most disorders begin early in life. Co-morbidity rates among mental disorders range from 44% to 94%. Correlates of increased rates of mental disorders and co-morbidity were: female gender (except for substance disorders), not being married, low social class, and poor somatic health status. Health care utilization for mental disorders depended on co-morbidity (30% in 'pure', 76% in highly co-morbid cases) and varied from 33% for substance use disorders to 75% for panic disorder. CONCLUSIONS: Results confirm and extend results from other national studies using the same assessment instruments with regard to prevalence, co-morbidity and sociodemographic correlates, covering a broader range of DSM-IV disorders [i.e. somatoform disorders, all anxiety disorders (except PTSD), mental disorders due to substance or general medical factor, eating disorders]. Intervention rates were higher than in previous studies, yet still low overall.

Adolescent↗
PubMed2004

Mechanisms of relapse prevention in schizophrenia.

INTRODUCTION: A relapse can be expected in 70 % of patients after the first schizophrenic episode; in parallel 70 % of patients show an incomplete remission of the disorder after the first episode. This includes a cognitive decline and persistence of schizophrenic negative symptoms, often associated with social disabilities, social decline and a worsened quality of life. The risk for a relapse after a schizophrenic episode remains increased throughout the patient's lifetime. Moreover, the risk for chronic disorder increases with every relapse of the patient. Therefore relapse prevention is a primary focus in the treatment of schizophrenia. METHODS: Studies point out that atypical antipsychotics have advantages in relapse prevention of schizophrenia compared to the "classical" antipsychotics, although comparative studies are still lacking. RESULTS: The main risk factor for a relapse is the withdrawal of antipsychotic medication. Nonbiological factors such as high-expressed emotions, adverse life events and stress contribute to an increased risk of schizophrenic relapse. Studies of relapse after withdrawal of antipsychotic medication revealed that noradrenergic, serotonergic, and dopaminergic neurotransmission are involved, low serotonergic and high dopaminergic neurotransmission are associated with a relapse, and possibly high noradrenergic neurotransmission plays a role in short-term relapses. Inflammation and the activation of certain cytokines, which have rarely been studied to date, seem to have an even higher impact on schizophrenic relapse. Methodological aspects of these studies are discussed. CONCLUSION: Biological mechanisms of relapse may not become fully elucidated before the mechanisms of the schizophrenic pathophysiology are clarified.

Biomarkers↗
PubMed2004

Psychotropic effects of COX-2 inhibitors--a possible new approach for the treatment of psychiatric disorders.

Cyclooxygenase-2 (COX-2)--constitutively expressed in the CNS--is suggested to have an important functional role in the CNS. COX-2 interacts with neurotransmitters such as acetylcholine, serotonin, and glutamate, but is also involved in the regulation of immune system and in inflammation in the central nervous system (CNS) via effects of prostaglandins, in particular prostaglandin E (2). Recently, a role for the new generation of selective COX-2 inhibitors in the treatment of psychiatric disorders is discussed. Until now, COX-2 inhibitors have failed to show therapeutic effects in Alzheimer's disease, but studies from basic research point to a possible effect on cognition. A clinical effect of the COX-2 inhibitor celecoxib on cognition was observed in schizophrenic patients. The therapeutic effect of celecoxib add-on treatment to the atypical antipsychotic risperidone, however, is not restricted to cognition. A general effect on symptoms of schizophrenia was observed, which supports the view that an immunological/inflammatory process is involved in the pathogenesis of schizophrenia. In depression, however, signs of inflammation have been described since many years. Although results of clinical studies with COX-2 inhibitors in depression are still lacking, clinical improvement of a depressive syndrome has been observed in patients, who have been treated with rofecoxib due to other indications. These preliminary clinical data are encouraging for therapeutic effects of the selective COX-2 inhibitors in psychiatric disorders, although these effects have to be confirmed in bigger clinical studies.

Antipsychotic Agents↗
PubMed2004

Zotepine versus placebo in the treatment of schizophrenic patients with stable primary negative symptoms: a randomized double-blind multicenter trial.

BACKGROUND: In contrast to traditional antipsychotic medication, newer, the so called atypical antipsychotic drugs promise to reduce primary negative symptoms in both, acute and chronic schizophrenia and improve quality of life. Zotepine, a D (2)5HT (2A) antagonist, was compared to placebo in this clinical trial to address these issues. METHODS: In an adaptive, 8-week multicenter, double-blind, randomized, parallel group study, efficacy and tolerability as well as influence on quality of life of zotepine and placebo were compared in 80 schizophrenic patients (53 % males, age 41 +/- 11 years) who experienced stable primary negative symptoms. Efficacy was assessed using the PANSS (primary outcome criterion: PANSS negative score), CGI, and MADRS; safety was controlled by EPS (Simpson-Angus Scale), TDRS and adverse events. Quality of life was evaluated with the SF-36 health questionnaire. RESULTS: After eight weeks of treatment with an average dose of 131 +/- 49 mg/day of zotepine, no superior efficacy of zotepine compared to placebo with respect to the PANSS subscale "negative symptoms could be demonstrated. Although patients receiving zotepine showed a pronounced reduction (per protocol set: -7.8 +/- 5.8) during treatment, it was not statistically different from a marked placebo response (-6.5 +/- 5.8). Similar small but not significant differences between zotepine and placebo were found in other subscales of the PANSS, the CGI and the MADRS. With regards to the quality of life assessment, patients under zotepine showed better results in the physical component scale and psychological well-being scale. In general, zotepine was well tolerated and there was no excess of extrapyramidal symptoms compared to placebo. CONCLUSIONS: Zotepine was not superior to placebo in reducing the severity of stable primary negative symptoms in schizophrenic patients in this trial. The main reasons for this finding were a high placebo response in a selected population, a probably too low dose of zotepine, and a short study period. However, several findings show clinical benefit of zotepine therapy in efficacy and quality of life.

Adolescent↗
PubMed2004

Experimental infections of neonatal mice with cysts of Giardia lamblia clone GS/M-83-H7 are associated with an antigenic reset of the parasite.

Transmission of the protozoan parasite Giardia lamblia from one to another host individuum occurs through peroral ingestion of cysts which, following excystation in the small intestine, release two trophozoites each. Many studies have focused on the major surface antigen, VSP (for variant surface protein), which is responsible for the antigenic variability of the parasite. By using trophozoites of G. lamblia clone GS/M-83-H7 (expressing VSP H7) and the neonatal mouse model for experimental infections, we quantitatively assessed the process of antigenic variation of the parasite on the transcriptional level. In the present study, variant-specific regions identified on different GS/M-83-H7 vsp sequences served as targets for quantitative reverse transcription-PCR to monitor alterations in vsp mRNA levels during infection. Respective results demonstrated that antigenic switching of both the duodenal trophozoite and the cecal cyst populations was associated with a massive reduction in vsp H7 mRNA levels but not with a simultaneous increase in transcripts of any of the subvariant vsp genes analyzed. Most importantly, we also explored giardial variant-type formation and vsp mRNA levels after infection of mice with cysts. This infection mode led to an antigenic reset of the parasite in that a VSP H7-negative inoculum "converted" into a population of intestinal trophozoites that essentially consisted of the original VSP H7 type. This antigenic reset appears to be associated with excystation rather than with a selective process which favors expansion of a residual population of VSP H7 types within the antigenically diversified cyst inoculum. Based on these findings, the VSP H7 type has to be regarded as a predominant variant of G. lamblia clone GS/M-83-H7 which (re-)emerges during early-stage infection and may contribute to an optimal establishment of the parasite within the intestine of the experimental murine host.

Animals↗
PubMed2003

PCR-based detection of canine Leishmania infections in formalin-fixed and paraffin-embedded skin biopsies: elaboration of a protocol for quality assessment of the diagnostic amplification reaction.

Diagnosis of the cutaneous form of canine leishmaniosis is mostly performed by histological or immunohistological examination of skin biopsies. In modern histology, the polymerase chain reaction (PCR) has gained increasing importance as a complementary tool to directly demonstrate the presence of parasite DNA in the tissue sections. For the present study, a previously described Leishmania-PCR has been further developed and optimised in view of its practicability for routine histological application. Since formalin-fixation of histological specimens causes partial DNA-destruction, which may hamper diagnostic PCR analysis, primers specific for the highly conserved alpha-actin gene sequences were used to pre-diagnostically assess the isolated sample-DNA for its functionality in a PCR-reaction. This alpha-actin-specific PCR detects DNA from a large variety of mammalian species and thus exhibits relevance for both human and veterinary medical application. A recombinant internal positive control was introduced to monitor possible sample-related inhibitory effects during the amplification reaction. We performed a retrospective evaluative study with 18 formalin-fixed samples from dogs with suspected or proven leishmaniosis. Six samples were PCR-incompatible. In turn, 9 of the other 12 samples were PCR-positive, and immunohistochemical results matched these findings. Based on these technical achievements, the Leishmania-PCR proved to be a valuable tool to complement conventional histological and immunohistological methods for diagnosis of cutaneous leishmaniosis in formalin-fixed, paraffin-embedded skin biopsies.

Actins↗
PubMed2003

[Visual search in healthy persons and Alzheimer's patients: relating cognitive function to clinical practice].

Visual search is a complex and highly relevant cognitive task. Hypotheses about the processes involved have been derived from experimental psychology and modified by recent functional imaging methods revealing the underlying neuronal networks. To close the gap between theoretical implications and clinical practice, models of visual search are employed to explain visual search impairments in patients with Alzheimer's disease.

Alzheimer Disease↗
PubMed2003

Vaccination of mice against experimental Neospora caninum infection using NcSAG1- and NcSRS2-based recombinant antigens and DNA vaccines.

NcSAG1 and NcSRS2, the two major immunodominant tachyzoite surface antigens of the apicomplexan parasite Neospora caninum, were investigated for their potential as vaccine candidates in mice. Recombinant recNcSRS2 and recNcSAG1 were expressed in Escherichia coli as poly-histidine-tagged fusion proteins. Separate groups of mice were immunized with purified recNcSAG1, recNcSRS2, or a combination of both, and were then challenged with N. caninum tachyzoites. Subsequent experiments included intramuscular vaccination of mice with the eukaryotic expression plasmid pcDNA3 containing either NcSRS2 or NcSAG1 cDNA inserts, followed by a single booster with the corresponding recombinant antigens. Immunization with a crude somatic antigen (NC1-extract) was included in the experiments. Following challenge, the presence of the parasite in the different organs was assessed by a N. caninum-specific PCR, while the parasite burden in infected brain tissue was assessed by quantitative real-time PCR. Immunization of mice employing individual recombinant antigens, or combined recNcSAG1/recNcSRS2, resulted in a lower degree of protection against cerebral infection, when compared to combined DNA/recombinant antigen vaccination. Serological analysis showed that this protective effect was associated with the occurrence of antibodies directed against native parasite antigens in those animals receiving combined DNA/recombinant antigen vaccination. Conversely, mice immunized with recombinant antigens alone generated antibodies recognizing only the recombinant antigens. Mice experiencing clinical signs such as walking disorders, rounded back, apathy and paralysis were observed only in the untreated positive control groups, but never in the vaccinated groups. Our results suggest that a combined DNA/recombinant antigen-vaccine, based on NcSAG1 and NcSRS2, respectively, exhibited a highly significant protective effect against experimentally induced cerebral neosporosis in mice.

Animals↗