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1.
Transl Psychiatry ; 12(1): 268, 2022 07 07.
Article in English | MEDLINE | ID: mdl-35794104

ABSTRACT

Although the currently available antidepressants are well established in the treatment of the major depressive disorder (MDD), there is strong variability in the response of individual patients. Reliable predictors to guide treatment decisions before or in an early stage of treatment are needed. DNA-methylation has been proven a useful biomarker in different clinical conditions, but its importance for mechanisms of antidepressant response has not yet been determined. 80 MDD patients were selected out of >500 participants from the Early Medication Change (EMC) cohort with available genetic material based on their antidepressant response after four weeks and stratified into clear responders and age- and sex-matched non-responders (N = 40, each). Early improvement after two weeks was analyzed as a secondary outcome. DNA-methylation was determined using the Illumina EPIC BeadChip. Epigenome-wide association studies were performed and differentially methylated regions (DMRs) identified using the comb-p algorithm. Enrichment was tested for hallmark gene-sets and in genome-wide association studies of depression and antidepressant response. No epigenome-wide significant differentially methylated positions were found for treatment response or early improvement. Twenty DMRs were associated with response; the strongest in an enhancer region in SORBS2, which has been related to cardiovascular diseases and type II diabetes. Another DMR was located in CYP2C18, a gene previously linked to antidepressant response. Results pointed towards differential methylation in genes associated with cardiac function, neuroticism, and depression. Linking differential methylation to antidepressant treatment response is an emerging topic and represents a step towards personalized medicine, potentially facilitating the prediction of patients' response before treatment.


Subject(s)
Depressive Disorder, Major , Diabetes Mellitus, Type 2 , Antidepressive Agents/therapeutic use , DNA , Depressive Disorder, Major/drug therapy , Depressive Disorder, Major/genetics , Diabetes Mellitus, Type 2/genetics , Epigenesis, Genetic , Epigenome , Genome-Wide Association Study/methods , Humans
2.
Purinergic Signal ; 17(3): 481-492, 2021 09.
Article in English | MEDLINE | ID: mdl-34282551

ABSTRACT

Extracellular nucleotides act as danger signals that orchestrate inflammation by purinergic receptor activation. The expression pattern of different purinergic receptors may correlate with a pro- or anti-inflammatory phenotype. Macrophages function as pro-inflammatory M1 macrophages (M1) or anti-inflammatory M2 macrophages (M2). The present study found that murine bone marrow-derived macrophages express a unique purinergic receptor profile during in vitro polarization. As assessed by real-time polymerase chain reaction (PCR), Gαs-coupled P1 receptors A2A and A2B are upregulated in M1 and M2 compared to M0, but A2A 15 times higher in M1. The ionotropic P2 receptor P2X5 is selectively upregulated in M1- and M2-polarized macrophages. P2X7 is temporarily expressed in M1 macrophages. Metabotropic P2Y receptors showed a distinct expression profile in M1 and M2-polarized macrophages: Gαq coupled P2Y1 and P2Y6 are exclusively upregulated in M2, whereas Gαi P2Y13 and P2Y14 are overexpressed in M1. This consequently leads to functional differences between M1 and M2 in response to adenosine di-phosphate stimulation (ADP): In contrast to M1, M2 showed increased cytoplasmatic calcium after ADP stimulation. In the present study we show that bone marrow-derived macrophages express a unique repertoire of purinergic receptors. We show for the first time that the repertoire of purinergic receptors is highly flexible and quickly adapts upon pro- and anti-inflammatory macrophage differentiation with functional consequences to nucleotide stimulation.


Subject(s)
Inflammation Mediators/metabolism , Macrophages/metabolism , Receptors, Purinergic/biosynthesis , Transcriptome/physiology , Animals , Cell Polarity/physiology , Cells, Cultured , Mice , Receptors, Purinergic/genetics
3.
Med Klin Intensivmed Notfmed ; 115(3): 249-252, 2020 Apr.
Article in German | MEDLINE | ID: mdl-30535900

ABSTRACT

Acute necrotizing esophagitis ("black esophagus") is defined as complete necrosis of the esophageal mucosa, which typically affects the entire circumference. We report a case of a healthy 62-year-old woman, who became hemodynamically unstable due to stress cardiomyopathy with acute right heart failure. Transfusion-dependent anemia occurred 24 h later and an upper gastrointestinal endoscopy revealed a black discoloured mucosa of the distal esophagus. After hemodynamic stabilization and treatment with proton pump inhibitors and sucralfate, complete healing of the esophageal mucosa was achieved.


Subject(s)
Cardiomyopathies , Esophagitis/diagnosis , Esophagitis/drug therapy , Esophagitis/therapy , Takotsubo Cardiomyopathy , Acute Disease , Female , Humans , Middle Aged
4.
Proc Natl Acad Sci U S A ; 116(26): 12781-12786, 2019 06 25.
Article in English | MEDLINE | ID: mdl-31186356

ABSTRACT

How do fundamental concepts from economics, such as individuals' preferences and beliefs, relate to equally fundamental concepts from psychology, such as relatively stable personality traits? Can personality traits help us better understand economic behavior across strategic contexts? We identify an antisocial personality profile and examine the role of strategic context (the "situation"), personality traits (the "person"), and their interaction on beliefs and behaviors in trust games. Antisocial individuals exhibit a specific combination of beliefs and preferences that is difficult to reconcile with a rational choice approach that assumes that beliefs about others' behaviors are formed rationally and therefore, independently from preferences. Variations in antisocial personality are associated with effect sizes that are as large as strong variations in strategic context. Antisocial individuals have lower trust in others unless they know that they can punish them. They are also substantially less trustworthy, believe that others are like themselves, and respond to the possibility of being sanctioned more strongly, suggesting that they anticipate severe punishment if they betray their partner's trust. Antisocial individuals are not simply acting in their economic self-interest, because they harshly punish those who do not reciprocate their trust, although that reduces their economic payoff, and they do so nonimpulsively and in a very calculated manner. Antisocial individuals honor others' trust significantly less (if they cannot be punished) but also, harshly punish those who betray their trust. Overall, it seems that antisocial individuals have beliefs and behaviors based on a view of the world that assumes that most others are as antisocial as they themselves are.


Subject(s)
Antisocial Personality Disorder/psychology , Trust , Antisocial Personality Disorder/economics , Culture , Economics, Behavioral , Games, Experimental , Humans , Psychology, Social , Punishment
5.
Micron ; 119: 1-7, 2019 04.
Article in English | MEDLINE | ID: mdl-30639793

ABSTRACT

The ternary iron arsenide compound BaFe2As2 exhibits a structural phase transition from tetragonal to orthorhombic at a temperature of about 140 K. The twin lamellae arising below this transition temperature were studied in undoped single crystalline bulk and epitaxial thin film samples using electron backscatter diffraction in a scanning electron microscope equipped with a helium cryostat. Applying this technique on bulk single crystals a characteristic twin lamella size in the range of 0.1 µm up to a few µm was observed. In contrast, in epitaxially strained thin films the phase transition is not observed at temperatures above 19 K.

6.
Ophthalmologe ; 116(4): 372-375, 2019 Apr.
Article in German | MEDLINE | ID: mdl-29881876

ABSTRACT

Self-injurious behavior (nonsuicidal self-injury, NNSI) is a common phenomenon and occurs in Germany, especially in adolescence, with a lifetime prevalence of 25-35%. In adulthood autoaggressive behavior is usually associated with mental illness, such as borderline personality disorder, as in the presented case. Eye injuries are rare. The treating physician is faced with the difficulty of correctly classifying the injury and clarifying suicidal intentions. Patient care requires a lot of patience, empathy and time and has to include psychosocial aspects.


Subject(s)
Borderline Personality Disorder , Eye Injuries , Self-Injurious Behavior , Germany , Humans
7.
Psychol Med ; 47(16): 2879-2891, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28587695

ABSTRACT

BACKGROUND: Commonly observed distortions in decision-making among patients with major depressive disorder (MDD) may emerge from impaired reward processing and cognitive biases toward negative events. There is substantial theoretical support for the hypothesis that MDD patients overweight potential losses compared with gains, though the neurobiological underpinnings of this bias are uncertain. METHODS: Twenty-one unmedicated patients with MDD were compared with 25 healthy controls (HC) using functional magnetic resonance imaging (fMRI) together with an economic decision-making task over mixed lotteries involving probabilistic gains and losses. Region-of-interest analyses evaluated neural signatures of gain and loss coding within a core network of brain areas known to be involved in valuation (anterior insula, caudate nucleus, ventromedial prefrontal cortex). RESULTS: Usable fMRI data were available for 19 MDD and 23 HC subjects. Anterior insula signal showed negative coding of losses (gain > loss) in HC subjects consistent with previous findings, whereas MDD subjects demonstrated significant reversals in these associations (loss > gain). Moreover, depression severity further enhanced the positive coding of losses in anterior insula, ventromedial prefrontal cortex, and caudate nucleus. The hyper-responsivity to losses displayed by the anterior insula of MDD patients was paralleled by a reduced influence of gain, but not loss, stake size on choice latencies. CONCLUSIONS: Patients with MDD demonstrate a significant shift from negative to positive coding of losses in the anterior insula, revealing the importance of this structure in value-based decision-making in the context of emotional disturbances.


Subject(s)
Brain Mapping/methods , Caudate Nucleus/physiopathology , Cerebral Cortex/physiopathology , Decision Making/physiology , Depressive Disorder, Major/physiopathology , Prefrontal Cortex/physiopathology , Reward , Adult , Case-Control Studies , Caudate Nucleus/diagnostic imaging , Cerebral Cortex/diagnostic imaging , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Prefrontal Cortex/diagnostic imaging , Severity of Illness Index
8.
Int J Oral Maxillofac Surg ; 46(10): 1229-1236, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28579265

ABSTRACT

The primary objective of this study was to investigate the quality of life (QOL) of patients with oral squamous cell carcinoma (OSCC) undergoing curative neoadjuvant chemoradiotherapy followed by radical tumour resection and simultaneous oral cavity reconstruction, using two validated questionnaires. A secondary objective was to assess clinical variables predicting post-treatment dysfunction in chewing, saliva, and swallowing. Thirty-five patients with locally advanced OSCC who underwent preoperative chemoradiotherapy were recruited prospectively. All patients completed both the University of Washington Quality of Life version 4 questionnaire (UW-QOL) and the Functional Assessment of Cancer Therapy-Head & Neck version 4 questionnaire (FACT-H&N). UW-QOL and FACT-H&N items were associated with clinical variables. Nearly three-quarters of OSCC patients perceived good to excellent levels of overall QOL after preoperative chemoradiotherapy. Chewing difficulties, decreased salivary function, and swallowing dysfunction were the most frequent complaints of OSCC patients. Items related to food intake were significantly worse in OSCC patients older than 60 years and those with T4 tumours, as well as those without alcohol intake. Chewing, saliva, and swallowing are the most significant issues in patients with OSCC undergoing preoperative chemoradiotherapy. The results of this study may help guide treatment decisions for OSCC patients based on more accurate expectations of adverse effects of cancer treatment.


Subject(s)
Carcinoma, Squamous Cell/physiopathology , Carcinoma, Squamous Cell/therapy , Chemoradiotherapy , Deglutition Disorders/physiopathology , Mouth Neoplasms/physiopathology , Mouth Neoplasms/therapy , Quality of Life , Salivation/physiology , Stomatognathic System/physiopathology , Carcinoma, Squamous Cell/surgery , Humans , Middle Aged , Mouth Neoplasms/surgery , Neoadjuvant Therapy , Oral Surgical Procedures , Preoperative Care , Prospective Studies , Surveys and Questionnaires
9.
J Physiol Paris ; 110(3 Pt B): 190-199, 2016 10.
Article in English | MEDLINE | ID: mdl-27815181

ABSTRACT

The Electrosensory Lateral Line lobe (ELL) is the first central target where the electrosensory information encoded in the spatiotemporal pattern electroreceptor afferent discharges is processed. These afferents encode the minute amplitude changes of the basal electric field through both a change in latency and discharge rate. In the ELL the time and rate-coded input pattern of the sensory periphery goes through the granular cell layer before reaching the main efferent cells of the network: large fusiform (LF) and large ganglion (LG) cells. The evidence until now shows that granular cells are inhibitory. Given that large fusiform cells are excited by the sensory input, it remains a mystery how the afferent input produce excitation through a layer composed by only inhibitory cells. We addressed this problem by modeling how the known circuitry of the ELL could produce excitation in LF cells with only inhibitory granular cells. Alternatively we show that a network composed of a mix of excitatory and inhibitory granular cell not only performs better, as expected, carrying excitation to LF cells but it does so robustly and at higher sensitivity by enhancing the contrast of the electric image between the periphery and the ELLs output. We then show with refined histological methods that a subpopulation of the granular cells indeed are excitatory, providing the necessary input for this contrast enhancing mechanism.


Subject(s)
Electric Fish/physiology , Electric Organ/physiology , Pattern Recognition, Physiological/physiology , Animals , Electric Organ/cytology , Neurons/physiology
10.
Cancer Treat Rev ; 41(10): 960-70, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26604093

ABSTRACT

BACKGROUND: Plasma fibrinogen may be involved in several stages of cancer progression. Clinical studies have demonstrated that pretreatment plasma fibrinogen is associated with poor survival in various cancers. The aim of this meta-analysis was to examine the prognostic effect of circulating fibrinogen in solid tumors. MATERIALS AND METHODS: We searched Medline, EMBASE, Cochrane Database of Systematic Reviews, and meeting proceedings to identify studies assessing the effect of pretreatment plasma fibrinogen on survival of cancer patients. Pooled multivariable-adjusted hazard ratios (HRs) for overall survival (OS), disease-free survival (DFS), and cancer-specific survival (CSS) were estimated using random-effects models. RESULTS: Data from 52 observational studies and 15,371 patients were summarized. An elevated baseline plasma fibrinogen was significantly associated with worse OS (pooled HR = 1.69; 95% CI = 1.48­1.92). The highest negative effect of elevated plasma fibrinogen on OS was demonstrated in renal cell carcinoma (pooled HR = 2.22), followed by head and neck cancer (pooled HR = 2.02), and colorectal cancer (pooled HR = 1.89). The adverse prognostic impact of high plasma fibrinogen remained in both non-metastatic and metastatic disease and patients of different ethnicity. Patients with high baseline fibrinogen had a significantly shorter DFS (pooled HR = 1.52) and CSS (pooled HR = 2.50). CONCLUSIONS: An elevated pretreatment plasma fibrinogen significantly correlates with decreased survival in patients with solid tumors. Future clinical trials are warranted to determine whether plasma fibrinogen could be incorporated in cancer staging systems and whether fibrinogen-lowering therapies have a favorable effect on disease recurrence and mortality.


Subject(s)
Fibrinogen/metabolism , Neoplasms/blood , Disease Progression , Disease-Free Survival , Humans , Neoplasms/mortality , Prognosis , Proportional Hazards Models
11.
Psychol Med ; 45(6): 1241-51, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25277236

ABSTRACT

BACKGROUND: Depression is a prevalent disorder that significantly affects the social functioning and interpersonal relationships of individuals. This highlights the need for investigation of the neural mechanisms underlying these social difficulties. Investigation of social exchanges has traditionally been challenging as such interactions are difficult to quantify. Recently, however, neuroeconomic approaches that combine multiplayer behavioural economic paradigms and neuroimaging have provided a framework to operationalize and quantify the study of social interactions and the associated neural substrates. METHOD: We investigated brain activation using functional magnetic resonance imaging (fMRI) in unmedicated depressed participants (n = 25) and matched healthy controls (n = 25). During scanning, participants played a behavioural economic paradigm, the Ultimatum Game (UG). In this task, participants accept or reject monetary offers from other players. RESULTS: In comparison to controls, depressed participants reported decreased levels of happiness in response to 'fair' offers. With increasing fairness of offers, controls activated the nucleus accumbens and the dorsal caudate, regions that have been reported to process social information and responses to rewards. By contrast, participants with depression failed to activate these regions with increasing fairness, with the lack of nucleus accumbens activation correlating with increased anhedonia symptoms. Depressed participants also showed a diminished response to increasing unfairness of offers in the medial occipital lobe. CONCLUSIONS: Our findings suggest that depressed individuals differ from healthy controls in the neural substrates involved with processing social information. In depression, the nucleus accumbens and dorsal caudate may underlie abnormalities in processing information linked to the fairness and rewarding aspects of other people's decisions.


Subject(s)
Caudate Nucleus/physiopathology , Depressive Disorder/physiopathology , Interpersonal Relations , Morals , Nucleus Accumbens/physiopathology , Adult , Anhedonia/physiology , Female , Games, Experimental , Humans , Magnetic Resonance Imaging , Male , Reward , Young Adult
13.
Nat Commun ; 4: 2877, 2013.
Article in English | MEDLINE | ID: mdl-24309386

ABSTRACT

The discovery of superconductivity with a transition temperature, Tc, up to 65 K in single-layer FeSe (bulk Tc=8 K) films grown on SrTiO3 substrates has attracted special attention to Fe-based thin films. The high Tc is a consequence of the combined effect of electron transfer from the oxygen-vacant substrate to the FeSe thin film and lattice tensile strain. Here we demonstrate the realization of superconductivity in the parent compound BaFe2As2 (no bulk Tc) just by tensile lattice strain without charge doping. We investigate the interplay between strain and superconductivity in epitaxial BaFe2As2 thin films on Fe-buffered MgAl2O4 single crystalline substrates. The strong interfacial bonding between Fe and the FeAs sublattice increases the Fe-Fe distance due to the lattice misfit, which leads to a suppression of the antiferromagnetic spin density wave and induces superconductivity with bulk Tc≈10 K. These results highlight the role of structural changes in controlling the phase diagram of Fe-based superconductors.

14.
Leukemia ; 27(2): 295-304, 2013 Feb.
Article in English | MEDLINE | ID: mdl-22699455

ABSTRACT

Despite risk-adapted treatment, survival of children with relapse of acute lymphoblastic leukemia (ALL) remains poor compared with that of patients with initial diagnosis of ALL. Leukemia-associated genetic alterations may provide novel prognostic factors to refine present relapse treatment strategies. Therefore, we investigated the clinical relevance of 13 recurrent genetic alterations in 204 children treated uniformly for relapsed B-cell precursor ALL according to the ALL-REZ BFM 2002 protocol. The most common alterations were deletions of CDKN2A/2B, IKZF1, PAX5, ETV6, fusion of ETV6-RUNX1 and deletions and/or mutations of TP53. Multivariate analysis identified IKZF1 deletion and TP53 alteration as independent predictors of inferior outcome (P=0.002 and P=0.001). Next, we investigated how both alterations can improve the established risk stratification in relapsed ALL. Intermediate-risk relapse patients with low minimal residual disease are currently considered to have a good prognosis. In this group, deletion of IKZF1 and alteration of TP53 identify patients with significantly inferior outcome (P<0.001). In high-risk relapse patients, deletion of IKZF1 is strongly predictive of a second relapse after stem cell transplantation (P<0.001). We conclude that IKZF1 and TP53 represent relevant prognostic factors that should be considered in future risk assessment of children with relapsed ALL to indicate treatment intensification or intervention.


Subject(s)
Biomarkers, Tumor/genetics , Bone Marrow Neoplasms/diagnosis , Gene Deletion , Mutation/genetics , Neoplasm Recurrence, Local/diagnosis , Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/genetics , Bone Marrow Neoplasms/genetics , Bone Marrow Neoplasms/mortality , Child , DNA, Neoplasm/genetics , Female , Follow-Up Studies , Humans , Ikaros Transcription Factor/genetics , Male , Neoplasm Recurrence, Local/genetics , Neoplasm Recurrence, Local/mortality , Polymerase Chain Reaction , Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/mortality , Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/pathology , Prognosis , Risk Factors , Survival Rate , Tumor Suppressor Protein p53/genetics
15.
J Neurophysiol ; 104(4): 1955-68, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20685928

ABSTRACT

Weakly electric fish use electroreception for both active and passive electrolocation and for electrocommunication. While both active and passive electrolocation systems are prominent in weakly electric Mormyriform fishes, knowledge of their passive electrolocation ability is still scarce. To better estimate the contribution of passive electric sensing to the orientation toward electric stimuli in weakly electric fishes, we investigated frequency tuning applying classical input-output characterization and stimulus reconstruction methods to reveal the encoding capabilities of ampullary receptor afferents. Ampullary receptor afferents were most sensitive (threshold: 40 µV/cm) at low frequencies (<10 Hz) and appear to be tuned to a mix of amplitude and slope of the input signals. The low-frequency tuning was corroborated by behavioral experiments, but behavioral thresholds were one order of magnitude higher. The integration of simultaneously recorded afferents of similar frequency-tuning resulted in strongly enhanced signal-to-noise ratios and increased mutual information rates but did not increase the range of frequencies detectable by the system. Theoretically the neuronal integration of input from receptors experiencing opposite polarities of a stimulus (left and right side of the fish) was shown to enhance encoding of such stimuli, including an increase of bandwidth. Covariance and coherence analysis showed that spiking of ampullary afferents is sufficiently explained by the spike-triggered average, i.e., receptors respond to a single linear feature of the stimulus. Our data support the notion of a division of labor of the active and passive electrosensory systems in weakly electric fishes based on frequency tuning. Future experiments will address the role of central convergence of ampullary input that we expect to lead to higher sensitivity and encoding power of the system.


Subject(s)
Action Potentials/physiology , Electric Fish/physiology , Hair Cells, Ampulla/physiology , Neurons, Afferent/physiology , Animals , Electric Stimulation/methods , Female , Hair Cells, Ampulla/cytology , Male , Neurons, Afferent/cytology , Random Allocation
16.
J Fish Biol ; 74(1): 54-76, 2009 Jan.
Article in English | MEDLINE | ID: mdl-20735524

ABSTRACT

In this study, a first comparative investigation of all four species of Petrocephalus (P. bovei, P. bane, P. soudanensis and P. cf. pallidomaculatus) present in the Upper Volta system and their electric organ discharges (EOD) was conducted. It was found that P. bovei was the most widespread (in terms of habitat use), but in several places P. bovei, P. soudanensis and P. cf. pallidomaculatus occurred syntopically. All species emitted a triphasic signal, and with very few exceptions, the Petrocephalus species of the Upper Volta system could clearly be identified on the basis of their EOD waveforms. The most obvious differences between species in EOD waveforms were in amplitude of the last phase, total duration and fast Fourier transformation (FFT) peak frequency. No sexual dimorphism was present in the EOD of any species although external dimorphism, i.e. an indentation at the base of the anal fin of mature males, was common. The EOD waveform diversity in the Upper Volta principally resembled that found in four sympatric Petrocephalus species from the Ogooué system (Gabon) and might play a role in species recognition and speciation processes.


Subject(s)
Electric Fish/physiology , Electric Organ/physiology , Animals , Burkina Faso , Male , Sex Characteristics , Species Specificity
17.
J Physiol Paris ; 102(4-6): 233-45, 2008.
Article in English | MEDLINE | ID: mdl-18992811

ABSTRACT

This study is concerned with the origin of backpropagating action potentials in GABAergic, medium ganglionic layer neurones (MG-cells) of the mormyrid electrosensory lobe (ELL). The characteristically broad action potentials of these neurones are required for the expression of spike timing dependent plasticity (STDP) at afferent parallel fibre synapses. It has been suggested that this involves active conductances in MG-cell apical dendrites, which constitute a major component of the ELL molecular layer. Immunohistochemistry showed dense labelling of voltage gated sodium channels (VGSC) throughout the molecular layer, as well as in the ganglionic layer containing MG somata, and in the plexiform and upper granule cell layers of ELL. Potassium channel labelling was sparse, being most abundant in the deep fibre layer and the nucleus of the electrosensory lobe. Intracellular recordings from MG-cells in vitro, made in conjunction with voltage sensitive dye measurements, confirmed that dendritic backpropagation is active over at least the inner half of the molecular layer. Focal TTX applications demonstrated that in most case the origin of the backpropagating action potentials is in the proximal dendrites, whereas the small narrow spikes also seen in these neurones most likely originate in the axon. It had been speculated that the slow time course of membrane repolarisation following the broad action potentials was due to a poor expression of potassium channels in the dendritic compartments, or to their voltage- or calcium-sensitive inactivation. However application of TEA and 4AP confirmed that both A-type and delayed rectifying potassium channels normally contribute to membrane repolarisation following dendritic and axonal spikes. An alternative explanation for the shape of MG action potentials is that they represent the summation of active events occurring more or less synchronously in distal dendrites. Coincidence of backpropagating action potentials with parallel fibre input produces a strong local depolarisation that could be sufficient to cause local secretion of GABA, which might then cause plastic change through an action on presynaptic GABA(B) receptors. However, STP depression remained robust in the presence of GABAB receptor antagonists.


Subject(s)
Dendrites/physiology , Electric Fish/physiology , Feedback, Physiological/physiology , Neuronal Plasticity/physiology , Rhombencephalon/cytology , Synapses/physiology , 4-Aminopyridine/pharmacology , Action Potentials/drug effects , Action Potentials/physiology , Animals , Dendrites/drug effects , Dose-Response Relationship, Drug , Electric Stimulation/methods , Microtubule-Associated Proteins/metabolism , Neurons/cytology , Neurons/physiology , Potassium Channel Blockers/pharmacology , Potassium Channels/classification , Potassium Channels/metabolism , Sodium Channel Blockers/pharmacology , Sodium Channels/classification , Sodium Channels/metabolism , Tetraethylammonium/pharmacology , Tetrodotoxin/pharmacology
18.
Contrast Media Mol Imaging ; 2(1): 42-9, 2007.
Article in English | MEDLINE | ID: mdl-17318918

ABSTRACT

In order to image mRNA transcription by in vivo magnetic resonance imaging (MRI), two intracellular MR contrast agents were developed, which are composed of a Gd-DOTA complex, a peptide nucleic acid (PNA) sequence and a cell-penetrating peptide. One was designed to bind to mRNA of dsRed (red fluorescent protein originating from Discosoma coral) by its PNA sequence, whereas the second one contains a nonsense sequence with no natural counterpart. The conjugates were synthesized using a continuous solid-phase synthesis scheme and characterized by ESI-MS. Fluorescence studies showed that both contrast agents could enter efficiently into 3T3 cells in a concentration-dependent manner from 0.5 to 9.0 microM. The contrast agent was located predominantly in vesicles around the nucleus, whereas no uptake into the nucleus was observed. The results of in vitro MR studies showed a statistically significant increase of the intracellular relaxation rate R (1,cell) at a labeling concentration of only 0.5 microM, thus contrast enhancement was detectable too. These results suggest that the synthesized contrast agents could label cells for optical as well as MR imaging and in future might be useful to prove specific accumulation in cells containing target mRNA.


Subject(s)
Contrast Media/pharmacokinetics , Heterocyclic Compounds/pharmacokinetics , Image Enhancement/methods , Magnetic Resonance Imaging/methods , Organometallic Compounds/pharmacokinetics , Peptide Nucleic Acids/pharmacokinetics , Animals , Contrast Media/administration & dosage , Contrast Media/chemical synthesis , Dose-Response Relationship, Drug , Heterocyclic Compounds/administration & dosage , Metabolic Clearance Rate , Mice , NIH 3T3 Cells , Organometallic Compounds/administration & dosage , Peptide Nucleic Acids/administration & dosage
19.
Int J Artif Organs ; 30(1): 16-24, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17295189

ABSTRACT

BACKGROUND: Intradialytic morbid events (IMEs, mostly hypotension) are frequent complications during hemodialysis (HD). This study investigated whether automatic feedback control via adjustment of the ultrafiltration rate reduces IME frequency. METHODS: In this multi-center cross-over study, 56 hypotension-prone patients were treated both with standard HD (sHD, applying a constant ultrafiltration rate) and HD applying a blood volume controlled ultrafiltration rate (cHD). The relative blood volume (RBV) was continuously monitored. The individual relative blood volume limit (RBVcrit ) was determined from the measured RBV during initial sHD. During cHD, the ultrafiltration rate was automatically adjusted to keep the actual RBV above RBVcrit. RESULTS: In 3,081 HD treatments, slightly fewer IMEs were observed during cHD than during sHD (0.785+/-0.613 versus 0.695+/-0.547 per treatment, P=0.144). Less symptomatic events were seen during cHD: -13% for symptomatic hypotension (0.594 versus 0.685 per treatment, P=0.120), and -32% for cramps (0.049 versus 0.072 per treatment, P=0.009). Thirty-one patients with the highest IME rate (IME in at least every second treatment) especially benefited from cHD: 1.185+/-0.554 versus 0.979+/-0.543 IME per treatment (P=0.004). The reduction in blood pressure (BP) and the increase in heart rate were lower during the treatments with cHD than with sHD: systolic BP: -18.8+/-26.7 versus -22.2+/-28.9 mmHg (P=0.007), diastolic BP: -7.8+/-14.8 versus -9.1+/-15.3 mmHg (P=0.064), heart rate: 1.8+/-10.4 versus 2.3+/-11.6 per minute (P=0.014). Neither treatment duration nor ultrafiltration volume was significantly different between cHD and sHD. CONCLUSION: For cHD, less intradialytic morbid events were observed than for sHD, and pre- to post-dialytic changes in blood pressure and heart rate were less pronounced.


Subject(s)
Renal Dialysis/adverse effects , Renal Dialysis/methods , Aged , Blood Pressure , Blood Volume , Cross-Over Studies , Hemodiafiltration , Humans , Hypotension/etiology , Muscle Cramp/etiology , Ultrafiltration
20.
Cancer Inform ; 3: 399-420, 2007 Dec 12.
Article in English | MEDLINE | ID: mdl-19455257

ABSTRACT

Aiming to find key genes and events, we analyze a large data set on diffuse large B-cell lymphoma (DLBCL) gene-expression (248 patients, 12196 spots). Applying the loess normalization method on these raw data yields improved survival predictions, in particular for the clinical important group of patients with medium survival time. Furthermore, we identify a simplified prognosis predictor, which stratifies different risk groups similarly well as complex signatures. We identify specific, activated B cell-like (ABC) and germinal center B cell-like (GCB) distinguishing genes. These include early (e.g. CDKN3) and late (e.g. CDKN2C) cell cycle genes. Independently from previous classification by marker genes we confirm a clear binary class distinction between the ABC and GCB subgroups. An earlier suggested third entity is not supported. A key regulatory network, distinguishing marked over-expression in ABC from that in GCB, is built by: ASB13, BCL2, BCL6, BCL7A, CCND2, COL3A1, CTGF, FN1, FOXP1, IGHM, IRF4, LMO2, LRMP, MAPK10, MME, MYBL1, NEIL1 and SH3BP5. It predicts and supports the aggressive behaviour of the ABC subgroup. These results help to understand target interactions, improve subgroup diagnosis, risk prognosis as well as therapy in the ABC and GCB DLBCL subgroups.

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