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H Beckmann

Publications and source records attributed to H Beckmann.

At least 91 records · Page 5Linked to original sources
PubMed1995

Evidence against unusual sex concordance and pseudoautosomal inheritance in the catatonic subtype of schizophrenia.

The study is based on sibships with multiply afflicted members derived from a family study of consecutively admitted probands with catatonic schizophrenia. As shown recently, the clinical subtype of periodic catatonia, as defined by Leonhard, is compatible with a major gene effect and genetic anticipation; that is, the age of illness onset of the probands is significantly earlier than that of their parents. In the present study, 83 probands with the clinical subtype of periodic catatonia had 26 afflicted siblings that were distributed among 23 families. We analyzed sex-concordance and pseudoautosomal inheritance patterns. Stratifying the 26 afflicted siblings by sibship size and by the proband's sex, we did not find unusual sex-concordance rates in sibships afflicted with periodic catatonia. Further, there was no association between sex concordance and maternal or paternal origin of the disease. Thus, our results provide strong evidence against pseudoautosomal inheritance or sex-linked transmission in affected sibships in the obviously familial schizophrenic subtype of periodic catatonia.

Adult↗
PubMed1995

Reduced echogenicity of brainstem raphe specific to unipolar depression: a transcranial color-coded real-time sonography study.

Echogenicity of the brainstem raphe was assessed in patients with major depression, bipolar affective disorders, and schizophrenia and compared with healthy adults employing transcranial color-coded real-time sonography. Forty probands were enrolled in each group. A highly significant reduction in raphe echogenicity was detected only in patients suffering from major depression. Echogenicity of the raphe was independent of age or sex and did not correlate with severity of the depressive syndrome or patient state. These findings are suggestive of structural desintegration of the brainstem raphe in unipolar depression, an anatomical region assumed to be a biological focus in the pathogenesis of depressive syndromes.

Adult↗
PubMed1995

Regional differences in the interaction of the excitotoxins domoate and L-beta-oxalyl-amino-alanine with [3H]kainate binding sites in human hippocampus.

The excitotoxic amino acid domoate causes anterograde amnesia and memory deficits while the excitotoxin L-beta-oxalyl-amino-alanine (L-BOAA) is considered the causative agent of the motoneurone disorder, neurolathyrism. Employing quantitative autoradiography we investigated the potency of domoate and L-BOAA to inhibit [3H]kainate binding in human hippocampus. Domoate inhibited binding of [3H]kainate with inhibition constants between 5.8 +/- 2.8 nM (deep layers of gyrus parahippocampalis) and 200.9 +/- 247.8 nM (CA1 region of hippocampus). It was about a thousandfold more potent than L-BOAA with inhibition constants between 2.1 +/- 0.5 microM (superficial layers of gyrus parahippocampalis) and 51.0 +/- 41.9 microM (CA2/3 region of hippocampus). Interestingly, L-BOAA showed lowest affinity to [3H]kainate binding sites in those regions in which domoate showed highest affinity (e.g. CA2/3) and vice versa (e.g. CA1). These data further support the notion that the neurological symptoms observed after domoate intoxication are due to an excitotoxic action at kainate receptors and provide evidence for heterogeneity of kainate receptors in human hippocampus.

Aged↗
PubMed1995

Consensus on minimal criteria of clinical and neuropathological diagnosis of schizophrenia and affective disorders for post mortem research. Report from the European Dementia and Schizophrenia Network (BIOMED I).

The sophisticated analysis of and growing information on the human brain requires that acquisition, dissection, storage and distribution of rare material are managed in a professional way. In this publication we present the consensus of the European work group "European Dementia and Schizophrenia Network", granted by the BIOMED I project of the EU, on minimal neuropathological and clinical requirements to include brains of patients with schizophrenia and affective disorders in post mortem studies. The description of clinical prerequisites in different EU countries and institutions is followed by a consensus on tissue handling, a consensus on minimal neuropathological criteria and a consensus on minimal clinical diagnostic criteria including clinical vignette, family, social, education/professional and general medical histories, general physical history including neurostatus, neurological, psychiatric, medication and general pathological histories, psychostatus, laboratory tests and a history provided by family/health care giver questionnaire. This publication should give help to interconnect different European brain bank centers on a basis of standardized protocols.

Brain↗
PubMed1995

Periodic catatonia: a schizophrenic subtype with major gene effect and anticipation.

In a family study involving 139 probands with DSM-III-R catatonic schizophrenia and 543 first-degree relatives, we investigated age-specific morbidity risk according to Leonhard's clinical distinction between systematic and periodic catatonia. This dichotomy is based on different types of symptomatology, course, and outcome. In systematic catatonia the age-corrected morbidity risk was 4.6%. In periodic catatonia, however, there was an age-corrected morbidity risk with homogenous psychoses of 26.9%, and more parents than siblings were affected. This points strongly to a major gene effect in periodic catatonia. Furthermore, a pairwise comparison of patients and their parents revealed patterns of anticipation, i.e., the probands' age at the onset of disease was significantly earlier than that of their parents (P < 0.001). Similarly, anticipation was apparent in pedigrees with three successive generations affected. This inheritance pattern with homogenous psychoses and anticipation indicates that genes with trinucleotid repeat expansion or other repetitive elements affecting gene expression may be involved in the etiology of periodic catatonia. Thus, periodic catatonia as a specific clinical subtype of schizophrenia is a promising candidate for molecular genetic evaluation.

Adult↗
PubMed1995

Decreased catalase activity but unchanged superoxide dismutase activity in brains of patients with dementia of Alzheimer type.

"Oxidative stress" may be of significance in the etiopathogenesis of dementia of Alzheimer type (DAT). Therefore, we measured activities of the enzymes superoxide dismutase (SOD) and catalase (CAT), which detoxicate reactive oxygen species. Enzyme activities were measured postmortem in basal ganglia, cortical, and limbic brain regions of patients with DAT and age-matched controls. SOD activity increased with age in basal nucleus of Meynert. However, there was no significant difference in SOD activity between DAT and controls. CAT activity was independent of age and postmortem time. There were significant reductions in CAT activity in parietotemporal cortex, basal ganglia, and amygdala in DAT compared with controls (p < 0.05 to 0.01). Our findings are in line with the assumption that reactive oxygen species could contribute to the pathogenesis of DAT. Absence of these changes in basal nucleus of Meynert might reflect retrograde degeneration of cholinergic fibers.

Age Factors↗
PubMed1994

Reconstitution of transcription factor SL1: exclusive binding of TBP by SL1 or TFIID subunits.

RNA polymerase I and II transcription factors SL1 and TFIID, respectively, are composed of the TATA-binding protein (TBP) and a set of TBP-associated factors (TAFs) responsible for promoter recognition. How the universal transcription factor TBP becomes committed to a TFIID or SL1 complex has not been known. Complementary DNAs encoding each of the three TAFIs that are integral components of SL1 have not been isolated. Analysis of subunit interactions indicated that the three TAFIs can bind individually and specifically to TBP. In addition, these TAFIs interact with each other to form a stable TBP-TAF complex. When TBP was bound first by either TAFI110, 63, or 48, subunits of TFIID such as TAFII250 and 150 did not bind TBP. Conversely, if TBP first formed a complex with TAFII250 or 150, the subunits of SL1 did not bind TBP. These results suggest that a mutually exclusive binding specificity for TBP intrinsic to SL1 and TFIID subunits directs the formation of promoter- and RNA polymerase-selective TBP-TAF complexes.

Amino Acid Sequence↗
PubMed1994

Assembly of transcriptionally active RNA polymerase I initiation factor SL1 from recombinant subunits.

Initiation of ribosomal RNA synthesis by RNA polymerase I requires the promoter selectivity factor SL1, which consists of the TATA-binding protein, TBP, and three associated factors, TAFIS 110, 63, and 48. Here the in vivo and in vitro assembly of functional SL1 complexes from recombinant TAFIS and TBP are reported. Complexes containing TBP and all three TAFIS were as active in supporting transcription from the human ribosomal RNA gene promoter as endogenous SL1, whereas partial complexes without TBP did not efficiently direct transcription in vitro. These results suggest that TAFIS 110, 63, and 48, together with TBP, are necessary and sufficient to reconstitute a transcriptionally active SL1 complex.

DNA-Binding Proteins↗
PubMed1994

Memantine inhibits [3H]MK-801 binding to human hippocampal NMDA receptors.

The antispastic agent and N-methyl-D-aspartate (NMDA) receptor antagonist memantine has recently been proposed as a neuroprotective drug for use in patients with dementia syndromes with primarily temporal lobe pathology, e.g. senile dementia of Alzheimer type or dementia in Parkinson's disease. In a quantitative autoradiographic study in human post mortem hippocampus, memantine was able to inhibit binding of the noncompetitive NMDA-antagonist [3H]MK-801 ((+)-5-methyl-10,11-dihydro-5H-dibenzo(a,d)cyclohepten-5,10-imine maleate) with inhibition constants between 3 and 10 microM, being about a factor of 10 more potent than the dissociative anaesthetic and NMDA receptor antagonist (+/-)ketamine. As these inhibition constants are well within the therapeutic concentration range of memantine, antagonism of endogenous glutamate at limbic NMDA receptors may be one molecular mechanism by which memantine is beneficial in dementia syndromes.

Aged↗
PubMed1994

Excitotoxins L-beta-oxalyl-amino-alanine (L-BOAA) and 3,4,6-trihydroxyphenylalanine (6-OH-DOPA) inhibit [3H] alpha-amino-3- hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) binding in human hippocampus.

Excitotoxins L-beta-oxalyl-amino-alanine (L-BOAA) and 3,4,6-trihydroxyphenylalanine (6-OH-DOPA) have been investigated with regard to their potency to inhibit [3H] alpha-amino-3-hydroxy-5-methyl-4- isoxazole-propionic acid (AMPA) binding in human hippocampus in a quantitative autoradiographic study. With dissociation constants (KD) of [3H]AMPA binding and inhibition concentrations (IC50) of L-BOAA, 6-OH-DOPA and L-glutamate obtained from saturation and displacement experiments inhibition constants (Ki) for the inhibition of [3H]AMPA binding in individual hippocampal subregions could be calculated. They were between 5.2 +/- 2.9 and 35.1 +/- 39.9 microM for L-BOAA and 39.1 +/- 26.8 and 59.4 +/- 44.1 microM for 6-OH-DOPA. L-BOAA was equally potent as the endogenous agonist L-glutamate with Ki's between 13.1 +/- 3.9 and 21.4 +/- 12.1 microM (n = 4, mean +/- S.D.). Limbic system symptoms like cognitive deficits, mood disturbances and vivid dreams observed in patients with the motor neuron disease neurolathyrism may thus well be mediated by agonistic action of L-BOAA at AMPA glutamate receptors in hippocampus.

Aged↗
PubMed1994

Circumscribed malformation and nerve cell alterations in the entorhinal cortex of schizophrenics. Pathogenetic and clinical aspects.

A postmortem histological comparison of 5 selected cases of schizophrenia with 5 non-schizophrenic controls showed a circumscribed malformation of the entorhinal cortex. The cortical alterations consisted mainly of a lack or a change of the characteristic island formations in layer II pre-alpha. Further, there were atypical neurons in layers II and III showing a conspicuous decrease of volume, often a change of the shape. They lay either in clusters or in columnar formations. These cells were considered "young neurons". The changes varied considerably from case to case and sometimes extended to all entorhinal layers. In one case the extension of the changes is described by means of serial sections in steps which extend over the whole rostral entorhinal region. Here, the striking architectural changes were formed in an exactly circumscribed sector and did not extend to the rostral hippocampal formation. On the whole, the changes are regarded as local migrational disturbances that occur during the second trimester of brain development. Neuronal displacements like these could give rise to various aberrant connections within the limbic system and related structures (e.g. the central position of the entorhinal region in circuits such as the entorhino-hippocampal loop, entorhinol-insula and entorhino-orbitofrontal reciprocal connections). Whereas alterations of the genetic programming of cell migrations may be suspected, various environmental influences (e.g. viral infections during the months III-V of pregnancy) appear to play a significant role. The malformations may be a decisive vulnerability factor for the later manifestation of the illness.

Adult↗
PubMed1994

Triplet repeats in clinical subtypes of schizophrenia: variation at the DRPLA (B 37 CAG repeat) locus is not associated with periodic catatonia.

Clinical evidence for a dominant mode of inheritance and anticipation in periodic catatonia, a distinct subtype of schizophrenia, indicates that genes with triplet repeat expansions or other unstable repetitive elements affecting gene expression may be involved in the etiology of this disorder. Because patients affected with dentatorubral-pallidoluysian atrophy (DRPLA) may present with "schizophrenic" symptoms, we have investigated the DRPLA (B 37 CAG repeat) locus on chromosome 12 in 41 patients with periodic catatonia. The B 37 CAG repeat locus was highly polymorphic but all alleles in both the patient and control group had repeat sizes within the normal range. We conclude that variation at the DRPLA locus is unlikely to be associated with periodic catatonia. The evidence for dominant inheritance and anticipation as well as the high prevalence of human brain genes containing trinucleotide repeats justifies further screening for triplet repeat expansions in periodic catatonia.

Adult↗
PubMed1994

Interactions of neurotoxins with non-NMDA glutamate receptors: an autoradiographic study.

Neurotoxic substances are discussed to cause neurodegeneration by acting as excitotoxins on glutamate receptors. We investigated the properties of L-beta-oxalyl-amino-alanine (L-BOAA) and 3,4, 6-trihydroxyphenlyalanine (6-OH-Dopa) at the alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) glutamate receptor and that of L-BOAA and domoic acid at the kainate glutamate receptor in human hippocampus. (3H)AMPA binding in hippocampal subfields was inhibited by L-BOAA and 6-OH-Dopa with mean IC50-values in the low micromolar range. (3H)Kainate binding was inhibited by L-BOAA with similar potency as (3H)AMPA binding and by domoic acid with mean IC50-values in the low nanomolar range. These results support the notion that symptoms like anterograde amnesia and epileptic seizures seen in domoic acid intoxication and limbic symptoms, e.g. cognitive and mood impairment observed in neurolathyrism may be caused by excitotoxic action on non-NMDA receptors. The potent interaction of 6-OH-Dopa with the AMPA-receptor may point to a possible dopaminergic-glutamatergic interaction in the development of neurodegenerative diseases like Parkinson's and Huntington's disease.

Amino Acids, Diamino↗
PubMed1994

[Prenatal developmental disorders of brain structures in schizophrenic psychoses].

In recent years neuroimaging techniques have revealed various cerebral and structural variances in patients with schizophrenic psychoses. The best established findings are the enlargement of the lateral ventricles and discrete structural deficits in temporobasal structures of the cortex. Neuropathological investigations have detected subcortical as well as cortical variances. Subcortically, the volume of the striatum and the globus pallidus have been found to be enlarged in schizophrenics. Among the cortical deviations, the cytoarchitectonic disturbances of the rostral entorhinal region have been well documented and are especially important. According to neuropathological criteria, they are derived from disturbances of prenatal cell migration within the central nervous system. Due to its close anatomical and functional connection with the hippocampal formation and its being the assembly point of all sensory cortical areas, disturbances of this area could seriously impede the processing and filtering of information within the limbic system. The other hitherto reported structural anomalies, such as the disturbance to the radial order of hippocampal neurons, and the abnormal structures in the frontobasal orbital regions and the rostroventral insula, could be connected to the disturbances of migration within the entorhinal region; the former could be secondary, but still prenatal developments. Well documented are the architectonic changes in the rostral cingulate gyrus which is itself connected with the entorhinal region via the Papez circuit. These findings are supported and supplemented by the results of epidemiological studies which indicate a disturbance of brain development during the second trimenon of the prenatal period. Viral infections (Influenza A2) of mothers during this critical period appear to play an especially important role.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Pregnancy infections in mothers of chronic schizophrenic patients. The significance of differential nosology].

In a retrospective study, 16 of 80 mothers of chronic DSM III-R schizophrenics reported having had a serious infectious disease during pregnancy. Eleven of the infections had occurred during the second trimester. Influenza and the common cold with fever were frequent. Ten of 80 female controls also recalled having had an infectious illness during pregnancy. Compared to the controls, mothers of schizophrenics reported more infectious illness during pregnancy, particularly during the fifth month of gestation (p < 0.05). Mothers of familial and of sporadic DSM III-R schizophrenics reported equal frequencies of infections in pregnancy. In contrast, when Leonhard's classification of psychoses was applied, significant differences appeared. Infections during pregnancy were scarcely found in unsystematic schizophrenics (mainly genetically determined according to Leonhard). In systematic schizophrenics (mainly exogenously determined according to Leonhard), a significantly higher frequency of infectious diseases was reported for the second trimester as compred both to controls (p < 0.01) and to unsystematic schizophrenics (p < 0.001). Infections during the fifth month of gestation were exclusively reported in systematic schizophrenics. Thus, in the systematic forms of schizophrenia infections during the second trimester and particularly during the fifth month of gestation seem to play an important role in the etiology and seem to be of causal importance for the various cytoarchitectural abnormalities detected in the central nervous system of schizophrenics.

Adult↗
PubMed1993

3H-spiroperidol binding to peripheral mononuclear cells in schizophrenic and healthy subjects.

3H-spiroperidol binding to peripheral blood mononuclear cells was measured in 28 patients, who fulfilled DSM-III-R-criteria for schizophrenia and 17 healthy subjects. There were no significant differences in characteristic binding parameters (Kd, Bmax) between schizophrenic and healthy subjects. Moreover, there was no relation of binding parameters to any of the subtypes of schizophrenia or to the course of illness according to DSM-III-R-criteria. However, some patients exhibited higher Bmax values without having a unique clinical symptomatology according to known diagnostic criteria. Neuroleptic treatment had no consistent effect on binding parameters intraindividually. Kd and Bmax values were not related to age or gender. In conclusion, despite our previously reported improved methodology, we were not able to corroborate the clinical importance of this "peripheral marker" as a tool for diagnosing schizophrenia or for predicting the response to neuroleptic treatment in our sample of schizophrenic patients.

Adult↗
PubMed1993

Adenosine A1 receptors in human hippocampus: inhibition of [3H]8-cyclopentyl-1,3-dipropylxanthine binding by antagonist drugs.

Adenosine A1 receptors were visualized in human hippocampus using [3H]8-cyclopentyl-1,3-dipropylxanthine (DPCPX) as a radioactive ligand probe. The receptor antagonists caffeine, the xanthine derivative KFM 19 and the carbamazepine analogue oxcarbazepine displaced [3H]DPCPX binding homogeneously without any marked difference between the individual layers in the investigated hippocampal subregions (n = 4). Ki's in the individual layers were in a range between 8.5 +/- 6.5 microM and 18.9 +/- 16.0 microM for caffeine and 11.5 +/- 2.8 nM and 18.1 +/- 14.1 nM for KFM 19. Ki's could not be calculated for oxcarbazepine as the IC50's were greater than 100 microM with estimated IC25's varying between 51.2 +/- 53.3 microM and 179.9 +/- 89.9 microM. Antagonism of endogenous adenosine at A1 receptors may thus explain part of the clinical effects of caffeine in humans and possibly exclusively the behavioral effects of KFM 19 in non-human primates.

Aged↗