Beckmann and bergmann reply:
Explore the source record for details and available documents.
Journal Article↗
Biomedical subjects
H Beckmann
Publications and source records attributed to H Beckmann.
Linkage and family-based association study of schizophrenia and the synapsin III locus that maps to chromosome 22q13.
The human synapsin III gene (synapsin III) is a member of a neuron-specific phosphoprotein gene family involved in short-term neurotransmitter release. We mapped synapsin III to chromosomal region 22q13 (13.1-13.31) by fluorescence in situ hybridization, a region that has been identified as a potential schizophrenia susceptibility locus. The dinucleotide repeat marker D22S280 located in intron 5 of synapsin III was genotyped in a linkage and family-based association study to assess the role of the synapsin III locus in the etiology of schizophrenia. In 12 pedigrees with periodic catatonia comprising 135 individuals, we found exclusion of linkage of marker D22S280 using lod score analysis with autosomal dominant/recessive models as well as affected only LOD score methods with dominant/recessive models. In a family-based association study of 61 unrelated parent-offspring trios with schizophrenia (according to the the Diagnostic and Statistical Manual of Mental Disorders, fourth edition [DSM-IV, American Psychiatric Association, 1994]), we found no association of individual D22S280 alleles to disease. Results of a multiallelic transmission/disequilibrium test (TDT(max) = 3.00; P = 0.55) challenged the possibility that D22S280 alleles appear with DSM-IV schizophrenia more frequently than expected. In addition, no evidence for gender differences or parent-of-origin effects were found. Thus, the synapsin III locus at chromosome 22q13 is not likely to contain a schizophrenia susceptibility gene.
Adult↗
Identification of benzodiazepines in Artemisia dracunculus and Solanum tuberosum rationalizing their endogenous formation in plant tissue.
Sterile cultivated plant cell tissues and cell regenerates of several species were tested for their binding affinity to the central human benzodiazepine receptor. Binding activity was found in extracts of Artemisia dracunculus cell tissue (IC(50) = 7 microg/ml) and, to a lesser extent, in plant regenerates of potato herb (Solanum tuberosum). Preparative HPLC led to the isolation of fractions with a significant displacing potency in the benzodiazepine receptor binding assay. Using on-line HPLC-electrospray-tandem mass spectrometry (HPLC-ESI-MS/MS) in the "selected reaction monitoring" (SRM) mode, delorazepam and temazepam were found in amounts of about 100 to 200 ng/g cell tissue of Artemisia dracunculus, whereas sterile potato herb contained temazepam and diazepam ranging approximately from 70 to 450 ng/g cell tissue. It is the first report on the endogenous formation of benzodiazepines by plant cells, as any interaction of microorganisms and environmental factors was excluded.
Artemisia↗
[Differential diagnosis, course and outcome of postpartum psychoses. A catamnestic investigation].
In a polydiagnostic study, a systematically recruited collective of 34 women with a first-episode postpartum psychosis was reexamined after a period of 6-26 years (averaging 12.6 years) in order to establish lifetime-diagnoses according to ICD-10 and Leonhard's classification, and to determine course and outcome. According to ICD-10, unipolar depressive disorders (32%) and acute polymorphous psychotic disorders (28%) represented the most frequent diagnoses. Applying Leonhard's classification revealed a marked predominance of cycloid psychoses (62%) with the subform of motility psychosis being the most frequent diagnosis (38%). Schizophrenias occurred rarely according to both classifications. Investigating the long-term course, we found in 59% multiphasic disorders. The mean number of episodes per patient was 2.5 (range 2-6) with a mean duration of 9.8 weeks (SD = 5.2). 6 patients (18%) had undergone a monophasic course, in 4 cases (12%) the course was not determinable. 17 women (50%) had 19 further deliveries during the follow-up period. The frequency of relapses in connection with a further delivery was 47%. Administering the Strauss-Carpenter-Outcome-Scale revealed a favourable outcome with a mean value of 14.1 (SD = 2.83) for our total sample. Only 4 patients (12%) had never recovered fully since the onset of the illness. Our findings suggest that cycloid psychoses, in particular motility psychoses, account for the majority of postpartum psychoses, and do not support the hypothesis of a nosological independence of postpartum psychoses. They provide further evidence of a favourable prognosis of severe postpartum psychiatric disorder despite a relatively high rate of non-puerperal and especially puerperal relapses.
Adult↗
hKCNN3 which maps to chromosome 1q21 is not the causative gene in periodic catatonia, a familial subtype of schizophrenia.
The human calcium-activated potassium channel gene (hKCNN3, hSKCa3) contains two tandemly arranged, multiallelic CAG repeats located in exon 1 which result in short to moderate polyglutamine stretches of unknown functional significance. Case-control and family-based association studies suggested an association of hKCNN3 repeats with susceptibility for schizophrenia. Twelve multiplex pedigrees with periodic catatonia, a schizophrenia subtype with major gene effect and patterns of anticipation, were genotyped using the multiallelic hKCNN3 repeat polymorphism. Using a dominant model of inheritance with sex- and age-dependent penetrance classes, cumulative results showed exclusion of linkage of hKCNN3 to periodic catatonia under the assumption of genetic homogeneity with lod score of -48.01 at zero recombination fraction. Our results provide evidence that hKCNN3 is not the causative gene in the familial schizophrenia subtype of periodic catatonia. By fluorescent in situ hybridization we confirmed the assignment of hKCNN3 to chromosome 1q21 near the heterochromatin region. Linkage mapping showed segregation with marker D1S498 (theta = 0.05) and placed hKCNN3 in the genetic linkage map in a cluster of genes near the centromeric region of chromosome 1.
Adult↗
Naturally occurring benzodiazepines: current status of research and clinical implications.
Naturally occurring benzodiazepines (BZDs) were first detected in mammalian tissues in 1986. They comprise a variety of 1,4-benzodiazepines corresponding to drugs commercially available for the treatment of anxiety disorders, sleep disturbances and epileptic seizures. Several biosynthetic pathways leading to the formation of BZDs are currently being discussed and have led to the proposition of possible precursor molecules. For years, the identification of naturally occurring BZDs in mammalian organisms was mostly confined to post mortem CNS material for sensitivity reasons. While radioimmunoassay and radioreceptor assay techniques have been tentatively applied to quantitations of genuine BZDs from human milk and cerebrospinal fluid, accurate measurements in peripheral blood have only recently become accessible, e. g., by gas chromatography/selected ion monitoring-mass spectrometry (GC/SIM-MS). This review summarizes existing evidence of benzodiazepines' occurrence in nature and discusses implications for neuropsychiatric disorders.
Animals↗
Ligand binding characteristics of a glycosylphosphatidyl inositol membrane-anchored HeLa cell folate receptor epitope-related to human milk folate binding protein.
The folate receptor (FR) in HeLa cells was characterized as to ligand binding mechanism, antigenic properties and membrane anchor in order to obtain information to be used for the design of biological agents targeting FR in malignant tumors. The receptor displayed the following binding characteristics in equilibrium dialysis experiments (37 degrees C, pH 7.4) with [3H] folate: a high-affinity type of binding that exhibited positive cooperativity with a Hill coefficient > 1.0 and an upward convex Scatchard plot, a slow radioligand dissociation at pH 7.4 becoming rapid at pH 3.5 and inhibition in the presence of other folates. The molecular size of the receptor was 100 kDa on gel filtration with Triton X-100, or similar to that of high molecular weight human milk folate binding protein (FBP). The latter protein represents a 25 kDa molecule which equipped with a hydrophobic glycosylphosphatidyl inositol (GPI) membrane anchor susceptible to cleavage by phosphatidylinositol specific phospholipase C (PI-PLC) forms micelles of 1kDa size with Triton X-100. The HeLa cell FR immunoreacted with antibodies against purified human milk FBP in ELISA, and in a fluorescence activated cell sorting system, where HeLa cells exposed to increasing concentrations of antibody showed a dose-dependent response. Exposure to PI-PLC decreased the fraction of immunolabeled cells indicating a linkage of FR to cell membranes by a GPI anchor. HeLa cells incubated with radiofolate showed a continuous uptake with time, however, with a complete suppression of uptake in the presence of an excess of cold folate. Prewash of cells at acidic pH to remove endogenous folate increased the uptake. Binding and uptake of [3H] folate was increased in cells grown in a folate-deprived medium. The HeLa FR seems to be epitope related to human milk FBP.
Binding Sites↗
Exonic variants of the GABA(B) receptor gene and panic disorder.
The enhancement of GABAergic neurotransmission has been closely linked to antipanic drug efficacy. This is the first study to investigate a putative association of exonic sequence variants of the human GABA(B) receptor 1 (GABA(B)R1) gene and susceptibility to panic disorder. Three DNA sequence variants in exons 1a1, 7 and 11 were assessed by polymerase chain reaction-based restriction fragment length polymorphism in a case-control study among patients with panic disorder with and without agoraphobia (DSM III-R criteria) and blood donors. There was no indication of an increased vulnerability to panic disorder or agoraphobia with respect to the allelic variants under study.
Agoraphobia↗
Parvovirus B19 in idiopathic thrombocytopenic purpura.
Explore the source record for details and available documents.
Adult↗
Schizophrenias in the Wernicke-Kleist-Leonhard school.
Explore the source record for details and available documents.
History, 20th Century↗
The genetic heterogeneity of "schizophrenia".
The main reason for the inconsistent findings in schizophrenia research is the lack of diagnostic conformity. This has not changed markedly following the introduction of modern operational diagnostic systems. Taking schizophrenia as a disease entity or assuming schizophrenia spectrum psychoses to represent a continuum of diseases without any clear dividing lines, the results of family and twin studies point to a multifactorial etiology based on a polygenic mode of transmission. Further, then it has to be assumed a familial continuum from schizophrenia to affective psychosis and other spectrum disorders. However, in family and twin studies based on Leonhard's classification, there is clearcut evidence that schizophrenic spectrum psychoses have to be divided into clinical and etiological subgroups with a completely different genetic background. For example, systematic catatonia is, for the most part, a sporadic disease, whereas periodic catatonia aggregates in families in a manner consistent with a major gene effect. Further, the results indicate that schizophrenic spectrum psychoses consist of three main valid categories: cycloid psychoses, unsystematic schizophrenias and systematic schizophrenias. In the case of cycloid psychosis and systematic schizophrenias, genetic loading seem to be very low, while "environmental" factors, for example, birth complications, may play an important etiological role. Unsystematic schizophrenias, however, are predominantly inherited and "environmental" factors are not very prominent.
Adult↗
Polymorphic MAO-A and 5-HT-transporter genes: analysis of interactions in panic disorder.
Recurrent panic attacks, anticipatory anxiety and phobic avoidance characterise panic disorder. The influence of genetic factors on liability to the disease has been the object of several linkage and association studies and appears to relate to an oligo- or polygenic rather than a monogenic mode of inheritance. Recently, an excess of high activity monoamine oxidase A (MAO-A) gene promoter alleles was found in female patients with panic disorder. An analysis of possible synergistic effects of the MAO-A gene promoter variant and the short serotonin transporter (5-HTT) gene promoter variant in panic disorder was performed in a German and an Italian sample (combined panic disorder n = 144, combined controls n = 175). There was no significant difference in odds ratios, suggesting that the observed increase of genetic liability by the long MAO-A gene promoter allele is not modified by the 5-HTT gene promoter polymorphism.
Adult↗
Glutathione S-transferase metabolism of the antineoplastic pentafluorophenylsulfonamide in tissue culture and mice.
The microtubule disrupting agent 2-fluoro-1-methoxy-4-pentafluorophenylsu lfonamidobenzene (T138067) binds covalently and selectively to beta-tubulin and has been shown to evade drug-efflux pumps that confer multidrug resistance to other antimitotic drugs that are used in cancer chemotherapy (Shan et al., 1999). In addition to these resistance mechanisms, eukaryotic cells have developed other protection mechanisms that involve enzymes that modify electrophilic xenobiotics. To determine whether T138067 is a substrate for such enzymatic detoxification pathways, a metabolism study was initiated. GSH conjugation was shown to play a major role in T138067 metabolism. T138067-GSH conjugates were isolated from the culture media of T138067-treated cells and the bile of mice treated i.v. with T138067. The major T138067-GSH degradation products were also isolated from these sources. 19F NMR studies of the metabolites showed that metabolic conversions occurred through substitution of the para fluorine atom in the pentafluorophenyl ring of T138067. The T138067-GSH conjugate was also isolated from T138067 incubation buffer that had been exposed to mouse, rat, dog, or human liver slices, suggesting that this mechanism is not species-specific. All three human glutathione S-transferases (alpha, mu, and pi), which are expressed in a wide variety of tissues including human tumors, were shown to metabolize T138067 effectively in vitro. The combined data show that T138067 is being metabolized, in vitro and in vivo, predominantly via a glutathione S-transferase-mediated metabolic pathway.
Animals↗
Functional PAX-6 gene-linked polymorphic region: potential association with paranoid schizophrenia.
BACKGROUND: Early differentiation of the nervous system and adult CNS neuroplasticity is modulated by PAX-6. We have shown previously that a highly polymorphic, functional AC/AG repeat in the 5' regulatory region of the gene showed significantly increased promoter activity, if containing > or = 29 repeats, and that the heterozygous genotype (< or = 28/> or = 29) revealed increased mRNA PAX-6 levels in human brain tissue compared to the homozygous short variant. METHODS: In a case-control study of 655 unrelated individuals, allele frequencies and genotype distributions of the functional PAX-6 promoter polymorphism were investigated comprising patients with DSM-IV schizophrenia, patients with affective disorders, and population controls. RESULTS: No allelic or genotypic association of the PAX-6 promoter polymorphism to affective disorder or to schizophrenia as one disease entity was observed. After subtyping schizophrenia into paranoid and nonparanoid forms, potential evidence was found for a genotypic association of the high-activity variant with the paranoid subtype of schizophrenia (p = .02). The estimated odds ratio was 1.7 (95% CI .98 to 2.95) for those heterozygous and 1.4 (95% CI .82 to 2.42) for those heterozygous or homozygous for the high-activity variant compared to the homozygous low-activity variant. CONCLUSIONS: Our finding indicates that early developmental genes may be involved in the etiopathogenesis of schizophrenia subtypes via variable transcriptional regulation in the developing and adult human brain.
Adult↗
Selective, covalent modification of beta-tubulin residue Cys-239 by T138067, an antitumor agent with in vivo efficacy against multidrug-resistant tumors.
Microtubules are linear polymers of alpha- and beta-tubulin heterodimers and are the major constituents of mitotic spindles, which are essential for the separation of chromosomes during mitosis. Here we describe a synthetic compound, 2-fluoro-1-methoxy-4-pentafluorophenylsulfonamidobenzene (T138067), which covalently and selectively modifies the beta1, beta2, and beta4 isotypes of beta-tubulin at a conserved cysteine residue, thereby disrupting microtubule polymerization. Cells exposed to T138067 become altered in shape, indicating a collapse of the cytoskeleton, and show an increase in chromosomal ploidy. Subsequently, these cells undergo apoptosis. Furthermore, T138067 exhibits cytotoxicity against tumor cell lines that exhibit substantial resistance to vinblastine, paclitaxel, doxorubicin, and actinomycin D. T138067 is also equally efficacious in inhibiting the growth of sensitive and multidrug-resistant human tumor xenografts in athymic nude mice. These observations suggest that T138067 may be clinically useful for the treatment of multidrug-resistant tumors.
Animals↗
Developmental malformations in cerebral structures of schizophrenic patients.
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. 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 trimester of the prenatal period. Viral infections (Influenza A2) of mothers during this critical period appear to play an especially important role. Nevertheless, the interaction between a genetic predisposition and exogenous noxious agents in such cases still needs to be clarified in our understanding of the etiology of schizophrenic psychoses.
Brain↗
[Remarks on the contribution of D. Sigmund. Cycloid psychosis and empirical-statistical research. Nervenarzt (1998) 69:228-37].
Explore the source record for details and available documents.
Cyclothymic Disorder↗
Absence of a subgroup of chronic schizophrenia in monozygotic twins. Consequences for considerations on the pathogenesis of schizophrenic psychoses.
In the region of Lower Franconia, Germany, all twins born after 1930 and hospitalized for a schizophrenia spectrum psychosis were ascertained in a systematic twin study comprising 22 monozygotic (MZ) and 25 dizygotic (DZ) pairs. One aim of the study was to compare concordance rates between MZ and DZ pairs with regard to various diagnostic classifications. Two experienced psychiatrists independently classified the probands according to DSM-III-R, ICD-10, and Leonhard's classification. Schizophrenic psychoses were found among MZ and DZ pairs in equal proportions according to DSM-III-R and ICD-10 criteria. In contrast, when Leonhard's classification was applied it became apparent that systematic schizophrenias, which represent the core group of schizophrenias in Leonhard's nosology, were completely lacking among the 34 ill MZ twins. Among the 30 ill DZ twins, 6 suffered from a systematic schizophrenia (p < 0.01). Unsystematic schizophrenias and cycloid psychoses occurred among MZ twins at a frequency of 58.8% and 41.2%, respectively. In the course of his own twin-investigations, Leonhard also observed an absence of systematic schizophrenias in MZ twins, although his twins were not systematically ascertained. This striking finding requires an explanation regarding its significance for the etiology of chronic schizophrenic psychoses. In view of the absence of other conclusive theories, one speculative explanatory model is that specific psychosocial factors, i.e., a lack of communication during childhood, may result in distinct biological damage to functional brain systems and, thus, may play a role in the pathogenesis of these psychoses.
Adult↗