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Biomedical subjects

A Rohde

Publications and source records attributed to A Rohde.

At least 19 recordsLinked to original sources
PubMed2001

The syringaldazine-oxidizing peroxidase PXP 3-4 from poplar xylem: cDNA isolation, characterization and expression.

The cell wall polymer lignin is believed to be condensed by specific cell wall-localized oxidoreductases. In many plants species, including poplar, the peroxidase-directed oxidation of the lignin analogue syringaldazine (SYR) has been localized to cells that undergo secondary wall formation, a process that includes lignification. As a first step to analyse the corresponding peroxidases. we have isolated previously two anionic isoenzymes (PXP 3-4 and PXP 5) from poplar xylem (Populus trichocarpa), which use SYR as a substrate. Here, we demonstrate that these enzymes are responsible for the visualized SYR oxidation in the developing xylem. The cDNA that corresponds to PXP 3-4 was isolated and the deduced protein was found closely related to the other SYR-oxidizing peroxidase PXP 5 (ca. 98% of identity). PXP 3-4 was expressed in a baculovirus expression system yielding high levels of active peroxidase (3 mg/l medium). The heterologously produced protein showed characteristics similar to those of the corresponding protein from poplar xylem (enzymatic properties, isoelectric point, and migration in a native gel). PXP 3-4 was expressed in the stem and in the root xylem. The data demonstrate that PXP 3-4 (and/or PXP 5) are present in differentiating xylem. supporting a function in secondary cell wall formation.

Amino Acid Sequence↗
PubMed2001

[Psychologic effects of traumatic live deliveries].

OBJECTIVES: Traumatically experienced childbirth can lead to serious psychological disturbances postpartum. Dependent upon objective and subjective factors, some women may even develop the symptomatology of a posttraumatic stress disorder (PTSD). The aim of a pilot study was the evaluation of the frequency of traumatically experienced childbirth, of the effects of these traumatic experiences and possible risk factors for the development of PTSD. STUDY DESIGN: 976 women, who had given birth at the Bonn University Women's Hospital during 1997/1998, were retrospectively questioned regarding their experiences with pregnancy, childbirth and postpartum. 46 women, who described relevant psychological symptoms after childbirth, were personally interviewed. RESULTS: 424 women returned the completed questionnaire. 17.2% of the women reported anxiety postpartum, 9.4% depressive symptoms, 12% a mental re-experience of delivery within the first weeks postpartum, 3.8% were still suffering from these intrusions at the time of the study. In the first weeks after labor, nightmares were reported in 3.1%. In 4 cases, the full criteria for a PTSD were met. In 10 further cases, a subsyndromal form of this disorder was found. The case analysis showed that the development of PTSD symptoms was influenced by factors such as expectations, need for control, sense of shame and previous traumatic experiences. CONCLUSIONS: Psychological symptoms postpartum were reported frequently. Traumatically experienced childbirth can be responsible for specific short-term or long-term symptoms. In individual cases, a PTSD can develop after a traumatic delivery with long-term negative consequences for the health and mental condition of the mother, the mother-child-relationship and the desire for further pregnancy. In such cases, a specific psychotherapeutic treatment is always necessary.

Adult↗
PubMed2000

Hemopoietic lineage commitment decisions: in vivo evidence from a transgenic mouse model harboring micro LCR-betapro-LacZ as a transgene.

A substantial body of published data suggests activation of lineage-specific genes in multipotential hemopoietic cells before their unilineage commitment. Because the behavior and plasticity of cells isolated in vitro away from microenvironmental constraints exercised in vivo may be altered, one wonders whether similar findings can be observed in a physiologic setting in vivo. We used a transgenic mouse model harboring human micro LCR together with beta promoter sequences as a transgene to examine activation of lineage-specific programs in vivo. By using LacZ as a reporter, we had the ability to detect, quantitate, and select live cells with different levels of LacZ activation. We found strong expression of LacZ by X-gal staining in 2 lineages-erythroid and megakaryocytic. Activation in the latter was a novel finding not previously observed when similar transgenes were used. We also found activation of muLCR-betapro at low levels in progenitor cells of granulocytic-macrophagic, erythroid, or megakaryocytic lineage detected by in vitro assays, suggesting activation before commitment to a specific lineage pathway. In particular, the expression of LacZ was graded among progenitors, so that in a proportion of them activation occurred only after commitment to erythroid or megakaryocytic lineage. In addition, we found quantitative reduction in LacZ expression between fetal liver and bone marrow-derived cells, the basis of which is unclear. Collectively our data provide in vivo evidence supporting the view that lineage-specific genes are expressed in a graded fashion in pluripotential cells before their irreversible unilineage commitment. (Blood. 2000;95:1274-1282)

Animals↗
PubMed2000

Quantitative trait loci and candidate gene mapping of bud set and bud flush in populus.

The genetic control of bud phenology in hybrid poplar was studied by mapping quantitative trait loci (QTL) affecting the timing of autumn bud set and spring bud flush. The founders of the mapping pedigree were collected from widely separated latitudes to maximize segregating variation for dormancy-related traits in the F(2) generation-the female Populus trichocarpa parent is from Washington State (48 degrees N) and the male P. deltoides parent is from Texas (31 degrees N). Bud set and bud flush timing were measured on the F(2) generation in a replicated clonal field trial. Using a linkage map constructed of AFLP and microsatellite markers, three QTL controlling bud set and six QTL controlling bud flush were detected. Additionally, five candidate genes believed to be involved in perception of photoperiod (PHYB1, PHYB2) or transduction of abscisic acid response signals (ABI1B, ABI1D, and ABI3) were placed on the QTL map. PHYB2 and ABI1B were found to be coincident with QTL affecting bud set and bud flush.

Base Sequence↗
PubMed2000

ABI3 affects plastid differentiation in dark-grown Arabidopsis seedlings.

The Arabidopsis ABSCISIC ACID-INSENSITIVE3 (ABI3) protein has been identified previously as a crucial regulator of late seed development. Here, we show that dark-grown abi3 plants, or abi3 plants returned to the dark after germination in the light, developed and maintained an etioplast with a prominent prolamellar body at developmental stages in which the wild type did not. Overexpression of ABI3 led to the preservation of the plastid ultrastructure that was present at the onset of darkness. These observations suggest that ABI3 plays a role in plastid differentiation pathways in vegetative tissues. Furthermore, the analysis of deetiolated (det1) abi3 double mutants revealed that DET1 and ABI3 impinge on a multitude of common processes. During seed maturation, ABI3 required DET1 to achieve its full expression. Mature det1 abi3 seeds were found to be in a highly germinative state, indicating that germination is controlled by both DET1 and ABI3. During plastid differentiation in leaves of dark-grown plants, DET1 is required for the action of ABI3 as it is during seed development. Together, the results suggest that ABI3 is at least partly regulated by light.

Arabidopsis↗
PubMed1999

Carpel, a new Arabidopsis epi-mutant of the SUPERMAN gene: phenotypic analysis and DNA methylation status.

The carpel (car) mutation affects the morphology of reproductive organs in Arabidopsis thaliana. car flowers have an increased number of carpels, on average 2.7 +/- 0.8 instead of two in the wild type. Through allelism test with fon1-3 and analysis of the methylation state of the SUPERMAN (SUP) gene in car mutants, we show that car is an epi-mutation of SUP. The methylation pattern of car is clearly distinct from that of fon1-3, another epi-mutation of the SUP gene. Methylation was found predominantly in Cp(A/T)p(A/G) triplets and in CpG pairs. We suggest that the extensive SUP methylation in car has arisen from an abundant methylation of a single CpG site that was already present in abscisic acid-insensitive (abi3-4) mutants, from which car was segregating.

Arabidopsis↗
PubMed1999

Violence, criminal behavior, and the EEG: significance of left hemispheric focal abnormalities.

The authors studies the relationship of EEG abnormalities and violent criminal behavior in 222 defendants referred for psychiatric evaluation. There was no connection between the number of violent offenses and EEG abnormalities in general. Focal abnormalities, however, especially of the left hemisphere, were related to a significantly higher number of violent offenses. In many cases these abnormalities were accompanied by mental retardation, epilepsy, or earlier brain damage. The findings suggest that impairment of left hemisphere functions may enhance the propensity for violent behavior in a subgroup of offenders.

Adolescent↗
PubMed1998

Gene discovery in the wood-forming tissues of poplar: analysis of 5, 692 expressed sequence tags.

A rapidly growing area of genome research is the generation of expressed sequence tags (ESTs) in which large numbers of randomly selected cDNA clones are partially sequenced. The collection of ESTs reflects the level and complexity of gene expression in the sampled tissue. To date, the majority of plant ESTs are from nonwoody plants such as Arabidopsis, Brassica, maize, and rice. Here, we present a large-scale production of ESTs from the wood-forming tissues of two poplars, Populus tremula L. x tremuloides Michx. and Populus trichocarpa 'Trichobel.' The 5,692 ESTs analyzed represented a total of 3,719 unique transcripts for the two cDNA libraries. Putative functions could be assigned to 2,245 of these transcripts that corresponded to 820 protein functions. Of specific interest to forest biotechnology are the 4% of ESTs involved in various processes of cell wall formation, such as lignin and cellulose synthesis, 5% similar to developmental regulators and members of known signal transduction pathways, and 2% involved in hormone biosynthesis. An additional 12% of the ESTs showed no significant similarity to any other DNA or protein sequences in existing databases. The absence of these sequences from public databases may indicate a specific role for these proteins in wood formation. The cDNA libraries and the accompanying database are valuable resources for forest research directed toward understanding the genetic control of wood formation and future endeavors to modify wood and fiber properties for industrial use.

Arabidopsis↗
PubMed1998

Multiple epsilon-promoter elements participate in the developmental control of epsilon-globin genes in transgenic mice.

To delineate the regulation of the human epsilon-globin gene, we investigated epsilon-gene expression during the development of transgenic mice carrying constructs with epsilon-promoter truncations linked to a micro-locus control region (microLCR). Expression levels were compared with those of microLCR epsilon mice carrying a 2 kilobase epsilon-promoter and betaYAC controls. epsilon mRNA in the embryonic cells of microLCR (-179)epsilon mice were as high as in microLCR epsilon mice suggesting that the proximal epsilon-promoter contains most elements required for epsilon-gene activation. epsilon mRNA in adult microLCR (-179) epsilon mice was significantly lower than in the embryonic cells indicating that elements involved in epsilon-gene silencing are contained in the proximal epsilon-promoter. Extension of the promoter sequence to -463 epsilon decreased epsilon-gene expression in the definitive erythroid cells, supporting previous evidence that the -179 to -463epsilon region contains an epsilon-gene silencer. However, the epsilon-gene of the microLCR(-463)epsilon mice was not silenced in the definitive cells of fetal and adult erythropoiesis indicating that additional silencing elements are located upstream of position -463epsilon. These results provide in vivo evidence that multiple elements of the distal as well as the proximal promoter contribute to epsilon-gene silencing.

Animals↗
PubMed1998

Developmental specificity of the interaction between the locus control region and embryonic or fetal globin genes in transgenic mice with an HS3 core deletion.

The human beta-globin locus control region (LCR) consists of five erythroid-lineage-specific DNase I-hypersensitive sites (HSs) and is required for activation of the beta-globin locus chromatin domain and globin gene expression. Each DNase I-HS of the LCR consists of a highly conserved core element and flanking sequences. To analyze the functional role of the core elements of the HSs, we deleted a 234-bp fragment encompassing the core of HS3 (HS3c) from a beta-globin locus residing on a 248-kb beta-locus yeast artificial chromosome and analyzed its function in F2 progeny of transgenic mice. Human epsilon-globin gene expression was absent at day 10 and severely reduced in the day 12 embryonic erythropoiesis of mice lacking HS3c. In contrast, gamma-globin gene expression was normal in embryonic erythropoiesis but it was absent in definitive erythropoiesis in the fetal liver. These results indicate that the core element of HS3 is necessary for epsilon-globin gene transcription in embryonic cells and for gamma-globin gene transcription in definitive cells. Normal gamma-globin gene expression in embryonic cells and the absence of gamma-globin gene expression in definitive cells show that different HSs interact with gamma-globin gene promoters in these two stages of development. Such results provide direct evidence for developmental stage specificity of the interactions between the core elements of HSs and the promoters of the globin genes.

Animals↗
PubMed1998

Frequency and phenomenology of persisting alterations in affective, schizoaffective and schizophrenic disorders: a comparison.

Investigating the long-term outcome of affective, schizoaffective and schizophrenic disorders, a model that integrated the operationally gathered findings with the 'interactional atmosphere' experienced by the clinician was applied. Eight different types of phenomenological constellations of persisting alterations were delineated (depletion syndrome, apathetic-paranoid (respectively apathetic-hallucinatory) syndrome, adynamic deficiency syndrome, chronic psychosis, structural deformation, slight asthenic insufficiency syndrome, chronic subdepressive syndrome, chronic hyperthymic syndrome. Former assumptions that cross-sectionally the persisting alterations in affective disorders are usually indistinguishable from those in schizophrenia could not be confirmed.

Humans↗
PubMed1995

Validity of the negative/positive dichotomy of schizophrenic disorders under long-term conditions.

Based on the phenomenological distinction of positive and negative symptoms, some authors discuss the existence of two subtypes of schizophrenia (positive vs. negative schizophrenia). Investigating the long-term course of 100 schizophrenic patients (on average 23 years after onset) it was found that only 24% of the patients had a stable monomorphous course (only once type of episode). The results of the presented longitudinal study do not support the assumption of 'purely positive' or 'purely negative' schizophrenic disorders. The relevance of positive and negative onset of illness for the long-term course and outcome is discussed with reference to the literature.

Cognition Disorders↗