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Andreas Jansen

Publications and source records attributed to Andreas Jansen.

18 recordsLinked to original sources
PubMed2026

Associations between CRP-related DNA methylation, stress exposure, and depression severity in a longitudinal clinical cohort.

BACKGROUND: Environmental adversity is linked to major depressive disorder (MDD), potentially via sustained low-grade inflammation. However, serum markers such as C-reactive protein (CRP) are transient and sensitive to acute states. In contrast, epigenetic signatures of inflammation may provide a more stable trace of how stress becomes biologically embedded and contributes to depression risk over time. METHODS: In a subsample of the Marburg-Münster Affective Disorders Cohort Study (MACS; N = 579; 320 healthy controls, 259 with MDD), we examined whether early life adversity (ELA; CTQ) and recent life stress (RLS; LEQ) are associated with CRP-related DNA methylation (CRPm) at baseline. We further tested whether CRPm predicts depressive symptom severity (HAMD) at baseline and at two-year follow-up (n = 407). DNA was extracted from whole blood, and CRPm scores were computed using publicly available genome-wide summary statistics. RESULTS: CRPm explained 21.3% of the variance in serum high-sensitivity CRP (hsCRP). Higher CRPm was significantly associated with both ELA (b = 0.01, SE = 0.003, p = 0.017) and RLS (b = 0.01, SE = 0.004, p = 0.032), after adjusting for age and sex. CRPm also predicted depressive symptom severity at baseline (b = 0.68, SE = 0.27, p = 0.013) and at follow-up (b = 0.79, SE = 0.25, p = 0.002). These associations remained after controlling for white blood cell-type composition but were attenuated after adjusting for BMI and smoking. In contrast, hsCRP was not associated with adversity or depressive symptoms. CONCLUSION: Our study indicates that a methylation-based index of chronic inflammation is associated with stress exposure and depressive symptoms over time, in contrast to fluctuating serum hsCRP. The findings are more consistent with an indirect pathway in which environmental adversity is linked to inflammatory biology via stress-related health behaviors, rather than with a model of direct biological embedding.

Humans↗
PubMed2006

Brucella endocarditis in prosthetic valves.

Human brucellosis is a multiple organ disease that presents with fever and is most often transmitted via contaminated, unpasteurized goat milk and cheese. In chronic cases, focal complications (eg, spondylitis, neurobrucellosis and endocarditis) are frequently seen. Although the disease may be severely debilitating, the mortality rate is low. Fatal cases are often due to endocarditis. Because Brucella endocarditis is a rare complication (2% to 5%), therapeutic considerations are based on single-case experiences only. Therapy includes long-term antibiotic treatment using combinations of various antimicrobial drugs and surgical valve replacement when required. A case of Brucella endocarditis complicated by the infection of two valvular prostheses implanted after involvement of the mitral and aortic valve due to rheumatic fever is described. The patient was successfully treated by a medical and surgical approach. Therapeutic strategies in Brucella endocarditis are discussed in light of the current literature.

Anti-Bacterial Agents↗
PubMed2005

Transcranial magnetic stimulation--a sandwich coil design for a better sham.

OBJECTIVE: To improve the quality of TMS studies by developing a new sham condition. METHODS: We describe a novel and easily arranged TMS set-up of two standard TMS coils and a magnetic shield, stacked like a sandwich. In a first step we compare the magnetic field in the sham and verum conditions. In a second step we ask six subjects to rate the stimulation intensity. RESULTS: The magnetic field in the sham mode is reduced to about one eighth of that during verum stimulation. The attenuation of the magnetic field is not limited to the actual stimulation site but also effective at neighbouring brain areas, avoiding direct and indirect stimulation via connected neural pathways. This also minimizes stimulation of the skin, but as a consequence allows subjects to distinguish between verum and sham conditions when these are contrasted directly. The position of the coil system and the acoustic sensations are indistinguishable between sham and verum condition. Subjects are not able to discriminate TMS position and condition by external cues. CONCLUSIONS: The proposed TMS setup is simple and allows verum and sham TMS without interaction of the researcher. If used with the magnetic shield, the magnetic field in the brain is attenuated most. SIGNIFICANCE: With the sandwich TMS coil system it is possible to improve the quality of TMS studies.

Adult↗
PubMed2005

Abnormal brain activation during movement observation in patients with conversion paralysis.

Dissociative paralysis in conversion disorders has variably been attributed to a lack of movement initiation or an inhibition of movement. While psychodynamic theory suggests altered movement conceptualization, brain activation associated with observation and replication of movements has so far not been assessed neurobiologically. Here, we measured brain activation by functional magnetic resonance imaging during observation and subsequent imitative execution of movements in four patients with dissociative hand paralysis. Compared to healthy controls conversion disorder patients showed decreased activation of cortical hand areas during movement observation. This effect was specific to the side of their dissociative paralysis. No brain activation compatible with movement inhibition was observed. These findings indicate that in dissociative paralysis, there is not only derangement of movement initiation but already of movement conceptualization. This raises the possibility that strategies targeted at reestablishing appropriate movement conceptualization may contribute to the therapy of dissociative paralysis.

Adult↗
PubMed2005

Dominance for language and spatial processing: limited capacity of a single hemisphere.

Using functional magnetic resonance imaging during word generation and spatial judgement (Landmark task), we investigated how hemispheric specializations for language and spatial processing interact in healthy individuals. We found individuals with atypical, right-hemispheric dominance for language to have more bilateral activation during spatial judgement than individuals with typical, disjunct hemispheric specialization, that is, left dominance for language and right dominance for spatial tasks. These findings suggest that hemispheric specializations for language and spatial functions interfere to some extent and favour additional recruitment of the opposite hemispheres for spatial functions.

Adult↗
PubMed2005

Hippocampus activity differentiates good from poor learners of a novel lexicon.

Language proficiency is a key to academic and workplace success for native and non-native speakers. It is largely unknown, however, why some people pick up languages more easily than others. We used event-related functional magnetic resonance imaging (e-fMRI) to elucidate which brain regions are modulated during the acquisition of a novel lexicon and which of these learning-related activity changes correlated with general semantic language knowledge. Fourteen healthy young subjects learned a novel vocabulary of 45 concrete nouns via an associative learning principle over the course of five blocks during e-fMRI. As a control condition, subjects took part in a structurally identical "No-Learning" condition lacking any learning principle. Overall, increasing vocabulary proficiency was associated with (intercorrelated) modulations of activity within the left hippocampus and the left fusiform gyrus, regions involved in the binding and integration of multimodal stimuli, and with an increasing activation of the left inferior parietal cortex, the presumed neural store of phonological associations. None of these activity changes were observed during the control condition. Furthermore, subjects who showed less suppression of hippocampal activity over learning blocks scored higher on semantic knowledge in their native language and learned the novel vocabulary more efficiently. Our findings indicate that (a) the successful acquisition of a new lexicon depends on correlated amplitude changes between the left hippocampus and neocortical regions and (b) learning-related hippocampus activity is a stable marker of individual differences in the ability to acquire and master vocabularies.

Adult↗
PubMed2005

Crossed cerebro-cerebellar language dominance.

In addition to its traditional role in motor control, the cerebellum has been implicated in various cognitive and linguistic functions. Lesion, anatomic, and functional imaging studies indicate a link between left frontal language regions and the right cerebellum. To probe the specificity of this circuit, we examined the association between language-related lateralized activation of the frontal cortex with lateralized activation of the cerebellum. Functional magnetic resonance imaging (fMRI) was carried out during letter-cued word generation in 14 healthy subjects: 7 subjects displayed typical left-hemisphere and 7 subjects displayed atypical right-hemisphere language dominance. We found activation of the cerebellar hemisphere contralateral to the language-dominant cerebral hemisphere in each subject. The cerebellar activation was confined to the lateral posterior cerebellar hemisphere (lobule VI, VII B, Cr I, Cr II). This study demonstrates that crossed cerebral and cerebellar language dominance is a typical characteristic of brain organization. The functional significance of the reported activations can now be tested in patients with lesions of the lateral posterior cerebellum.

Adult↗
PubMed2005

Pulmonary melioidosis associated with bronchiolitis obliterans organizing pneumonia.

We report a case of pulmonary melioidosis associated bronchiolitis obliterans with organizing pneumonia (BOOP). While antibiotic treatment alone did not show any major effect, addition of corticosteroids resulted in rapid clinical improvement. To our knowledge this is the first documented case of melioidosis associated with organising pneumonia. The possible therapeutic implications for the treatment of severe pulmonary melioidosis are discussed.

Adult↗
PubMed2005

Atypical hemispheric dominance for attention: functional MRI topography.

The right hemisphere is predominantly involved in tasks associated with spatial attention. However, left hemispheric dominance for spatial attention can be found in healthy individuals, and both spatial attention and language can be lateralized to the same hemisphere. Little is known about the underlying regional distribution of neural activation in these 'atypical' individuals. Previously a large number of healthy subjects were screened for hemispheric dominance of visuospatial attention and language, using functional Doppler ultrasonography. From this group, subjects were chosen who were 'atypical' for hemispheric dominance of visuospatial attention and language, and their pattern of brain activation was studied with functional magnetic resonance imaging during a task probing spatial attention. Right-handed subjects with the 'typical' pattern of brain organization served as control subjects. It was found that subjects with an inverted lateralization of language and spatial attention (language right, attention left) recruited left-hemispheric areas in the attention task, homotopic to those recruited by control subjects in the right hemisphere. Subjects with lateralization of both language and attention to the right hemisphere activated an attentional network in the right hemisphere that was comparable to control subjects. The present findings suggest that not the hemispheric side, but the intrahemispheric pattern of activation is the distinct feature for the neural processes underlying language and attention.

Adult↗
PubMed2005

Leptospirosis in Germany, 1962-2003.

Epidemiologic trends of human leptospirosis in Germany were investigated by analyzing national surveillance data from 1962 to 2003 and by conducting a questionnaire-based survey from 1997 to 2000. After a steady decrease of leptospirosis incidence from 1962 to 1997, surveillance data indicate an increase in disease incidence to 0.06 per 100,000 (1998-2003). Of 102 laboratory-confirmed cases in humans from 1997 to 2000, 30% were related to occupational exposures. Recreational exposures were reported in 30% (including traveling abroad in 16%), whereas residential exposure accounted for 37% of the cases. Direct contact with animals, mostly rats and dogs, was observed in 31% of the cases. We conclude that recent changes in transmission patterns of leptospirosis, partially caused by an expanding rat population and the resurgence of canine leptospirosis, may facilitate the spread of the disease in temperate countries like Germany. Preventive measures should be adapted to the changing epidemiology of leptospirosis.

Adolescent↗
PubMed2004

Determining the hemispheric dominance of spatial attention: a comparison between fTCD and fMRI.

Human brain mapping allows the systematic assessment of interindividual differences in functional brain anatomy. Functional transcranial Doppler sonography (fTCD) is an imaging tool that allows for fast and mobile assessment of hemispheric lateralization of task-related brain activation. It is ideal to screen large cohorts of subjects. The goal of the present study was to investigate whether fTCD and functional magnetic resonance imaging (fMRI) determine hemispheric lateralization of brain activation related to visuospatial attention concordantly. Used together, fMRI and fTCD may then open up a wide range of potential applications in neuroscience. Fifteen subjects were examined both with fTCD and fMRI while they judged accuracy of line bisections (Landmark task). For fTCD, the maximal mean difference in stimulus-related relative cerebral blood flow velocity changes in the left and right middle cerebral arteries was assessed as the lateralization index LI(fTCD). For fMRI, two approaches were used to determine hemispheric dominance. First, we measured brain activity as the extent of the activated region, i.e., the number of activated voxels above a statistical threshold. Second, we calculated the magnitude of the fMRI signal change between the activation and the control task within a region of interest. Results of fTCD and fMRI were concordant in every single case. Therefore, scanning large cohorts with fTCD for hemispheric dominance during Landmark task will provide results consistent with fMRI. FMRI can then be used for in depth assessment of the specific patterns of activation.

Adult↗
PubMed2004

Task repetition can affect functional magnetic resonance imaging-based measures of language lateralization and lead to pseudoincreases in bilaterality.

Repeated functional magnetic resonance imaging (fMRI) during learning and recovery can inform us about functional reorganization in the brain. We examined how, in the absence of reorganization, simple task repetition affects measures of fMRI activation. We studied fMRI activation over 10 consecutive sessions of silent word generation in a healthy subject. Additionally, we performed functional transcranial Doppler sonography (fTCD) to learn about the temporal pattern of corresponding changes in cerebral blood flow velocity (CBFV) and pulsatility. With repetition, word generation-associated increases in heart rate diminished steadily. Task repetition also led to a net increase in CBFV bilaterally and to a bilateral increase in the number of activated voxels on fMRI. As a result, whereas the absolute interhemispheric difference of activated voxels remained constant, there was a decrease in the standard fMRI index for language lateralization [LIfMRI = 100 (activated voxels in left hemisphere - voxels in right)/(voxels in left + voxels in right)]. Thus task repetition can lead to changes in task-related autonomic drive and an augmentation of bihemispheric blood flow. This can mimic increasing bilaterality of brain activation.

Adult↗
PubMed2004

Word learning can be achieved without feedback: implications for aphasia therapy.

PURPOSE: Children acquire new words through exposure, without the necessity for explicit feedback by caregivers. In aphasia therapy, feedback to the patient is considered an important asset even though the empirical base demonstrating superior learning with online feedback is lacking. The present study examined if healthy adults and patients with chronic aphasia can acquire a new lexicon by intense frequency of exposure alone. METHODS: We compared learning rates with "frequency of exposure alone" (no-feedback condition: n=19 healthy adults; two patients with chronic Broca's and Wernicke's aphasia, respectively) with a condition where subjects additionally received online feedback (feedback condition; n=19). The learning principle was higher statistical co-occurrences of "correct" picture-pseudoword pairings as compared to "incorrect" pairings. In the feedback condition, immediate online feedback on the correctness of respective choices was additionally provided. RESULTS: Both healthy groups successfully acquired the vocabulary. Feedback led to a slight initial acceleration of learning but did not improve latency to peak performance or long-term retention of lexical knowledge. These findings show that high frequency interactive exposure is a potent word learning mechanism in adults and that feedback is not crucial. This is further corroborated by our successful training of two patients with chronic aphasia without online feedback. CONCLUSIONS: Our findings demonstrate that word re-learning in aphasia could benefit from maximizing on the frequency of exposure and exploiting the therapeutic principle of "massed practice", which has been successful in physical rehabilitation after stroke. Additionally, economizing on feedback may prevent patients becoming discouraged by continuous confrontation with their deficits.

Adult↗
PubMed2003

Adult autoimmune enteropathy treated successfully with tacrolimus.

BACKGROUND: Autoimmune enteropathy is a life-threatening, chronic disease of the small bowel mucosa, which generally responds well to steroids. Treatment requires long-term immunosuppression, and steroid-sparing treatment strategies are desirable. Azathioprine and cyclosporine A have limitations, however alternatives have not been described in adults. CASE REPORT: We present the case of a 54-year-old male patient with autoimmune enteropathy who responded initially to a standard treatment with steroids, but was dependent on 30 mg prednisolone. Medical treatment was changed to tacrolimus after renal function deteriorated under treatment with cyclosporine A. Under this regimen, small bowel histology normalized and the clinical condition is stable after 2 years of introduction of tacrolimus. CONCLUSION: This constitutes the first report of effective treatment of adult autoimmune enteropathy with tacrolimus, a substance with a similar mode of action to cyclosporine, but with fewer side effects and improved bioavailability.

Administration, Oral↗
PubMed2003

Functional magnetic resonance imaging mirrors recovery of visual perception after repetitive tachistoscopic stimulation in patients with partial cortical blindness.

We investigated three patients with partial cortical blindness after brain injury by means of functional magnetic resonance imaging (fMRI) before and after the application of a daily visual stimulation-therapy over a period of 6 months. Before therapy, fMRI data showed a severely reduced blood-oxygen-level-dependent (BOLD) signal in primary visual cortex when compared to healthy volunteers. Following several months of rehabilitative therapy a neuropsychological improvement of visual functions was accompanied by an increase in BOLD signal of residual perilesional regions whereas fMRI data of the control group remained unchanged. A high capacity of functional recovery and synaptic plasticity of surviving perilesional neuronal structures of primary visual cortex followed by an increased input into post-connected visual areas can be discussed as a basis for the reoccurrence of visual functions.

Adult↗