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M Drechsler

Publications and source records attributed to M Drechsler.

31 records · Page 2Linked to original sources
PubMed1993

Characterization of the transcriptional regulatory region of the human WT1 gene.

Specific control of the expression of the Wilms tumor gene WT1 is important for normal development of the kidney. In order to characterise the transcriptional control region of the WT1 gene we have isolated genomic clones spanning the upstream region, the first WT1 exon and the 5' end of the Wit1 gene. DNA sequencing revealed that the WT1 promoter lacks a TATA box or CCAAT motif and has a GC content of 71%. Four transcriptional start sites are clustered within a 32 bp region. GC-boxes are present at nucleotide positions -413, -160, +84 and +158. DNAase I protection assays with purified Sp1 protein revealed the existence of 11 different binding sites in the WT1 promoter. WT1 and Wit1 promoter activities were tested in COS-7 cells with luciferase reporter gene constructs either containing or lacking an SV40 enhancer. WT1 promoter activity was found in a fragment extending from 449 bp upstream to 201 bp downstream of the WT1 start site. It was 26 fold lower in the absence of the SV40 enhancer than in the presence. Cotransfection with a Sp1 expression vector stimulated both constructs 3-4 fold. Wit1 promoter activity was identified in a DNA fragment extending from 200 bp upstream of the putative Wit1 TATA box to 130 bp downstream. Several potential recognition sites for WT1/EGR, Pax-8, and GAGA-like transcription factors are present in the WT1 promoter.

Base Sequence↗
PubMed1992

Association of cyclic GMP-gated channels and Na(+)-Ca(2+)-K+ exchangers in bovine retinal rod outer segment plasma membranes.

1. Cyclic GMP-gated channels and Na(+)-Ca(2+)-K+ exchangers from bovine photoreceptors were examined by investigation of the Ca2+ fluxes from vesicles of rod outer segment (ROS) membranes and from proteoliposomes obtained by solubilization of the ROS membrane proteins and reconstitution in soy bean L-alpha-phosphatidylcholine (PC). 2. Whereas vesicles obtained by mild sonication of ROS membranes in a Ca(2+)-containing buffer yielded a maximal cyclic GMP-induced Ca2+ release of about 2.5% and a maximal Na(+)-induced Ca2+ release of about 7%, freezing and thawing of ROS membranes prior to sonication elevated these maximal Ca2+ releases to about 17% for cyclic GMP, and to about 34% for Na+. These observations are in agreement with the view that cyclic GMP-gated channels and Na(+)-Ca(2+)-K+ exchangers are localized only in the plasma membrane of the photoreceptors (which in bovine ROS makes up about 6% of the total membrane), whereas freezing and thawing results in fusion of disc and plasma membranes, thus leading to a distribution of these proteins over a much larger membrane area. 3. For fused ROS membranes, the cyclic GMP-releasable fraction of Ca2+ of 17% is an upper bound; assuming that the cyclic GMP-gated channels are randomly distributed we estimate that about 37% of the vesicles contain at least one cyclic GMP-gated channel. The mean diameter of the vesicles prepared by sonication was determined to be 0.12 +/- 0.04 micron, and therefore the fused ROS membranes contain about sixteen cyclic GMP-gated channels/microns 2. If all cyclic GMP-gated channels originated from the plasma membrane, we estimate that the plasma membrane contains about 270 cyclic GMP-gated channels/microns 2. 4. In vesicles prepared from fused ROS membranes, Na(+)-Ca2+ exchange after activation of the cyclic GMP-gated channels. On the other hand, after an exhaustive Na(+)-Ca2+ exchange, only little, if any, Ca2+ was released upon addition of cyclic GMP, demonstrating that cyclic GMP-gated channels and Na(+)-Ca(2+)-K+ exchangers occur on the same vesicle fraction. This observation suggests that Na(+)-Ca(2+)-K+ exchangers do not distribute independently of the cyclic GMP-gated channels upon membrane fusion but are apparently associated with the cyclic GMP-gated channels.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1991

Positional cloning and characterization of a paired box- and homeobox-containing gene from the aniridia region.

Based on the map location of the aniridia (AN) locus in human chromosomal band 11p13, we have cloned a candidate AN cDNA (D11S812E) that is completely or partially deleted in two patients with AN. The less than 70 kb smallest region of overlap between the two deletions encompasses the 3' coding region of the cDNA. This cDNA, which spans over 50 kb of genomic DNA, detects a 2.7 kb message specifically within all tissues affected in AN. The predicted polypeptide product possesses a paired domain, a homeodomain, and a serine/threonine-rich carboxy-terminal domain, structural motifs characteristic of certain transcription factors. The concordance between expression and pathology, map location, structure, and predicted function argues that the cDNA corresponds to the AN gene.

Amino Acid Sequence↗
PubMed1991

EELS data acquisition, processing and display for the Zeiss CEM 902 based on LOTUS 1-2-3: application examples from a biological system and inorganic transition metal compounds.

A personal computer combined with LOTUS 1-2-3 software, including the RS232 module of LOTUS MEASURE and a 12-bit ADC, has been used for data acquisition of electron energy-loss spectroscopy (EELS) spectra with the Zeiss CEM 902. The internal macro language of LOTUS 1-2-3 allows a menu-driven procedure. Macro-programs partly combined with external FORTRAN programs can be chosen from the menu for background subtraction, removal of multiple scattering effects by deconvolution, elemental quantification and several utilities. For special applications or conditions the macro programs can easily be modified. Spectra from crystals of two inorganic transition metal compounds, ruthenium trichloride and vanadium disulphide, and from a biological sample are presented as examples of the application of this software.

Animals↗
PubMed1990

Identification of precipitable Ca2+ by electron spectroscopic imaging and electron energy loss spectroscopy in the organ of Corti of the guinea pig.

Ca2+ cations were precipitated with potassium antimonate in the cochlea of the guinea pig, and the formed precipitates were localized by electron microscopy using either elastically or inelastically scattered electrons. The elemental composition of the precipitates was determined by electron spectroscopic imaging (ESI) and electron energy loss spectroscopy (EELS). It was found that calcium, antimony and oxygen were the dominating elements in the precipitates formed in different cell types in the inner ear.

Animals↗
PubMedDate not supplied

Common issues for parents in a methadone maintenance group.

Change has been noted in some of the group members. For example, one long-term group member who never spoke when she was in a previous group that focused on addiction-related problems has become the role model for other members. In this group, she says, she feels more competent. She is appropriately outspoken and has established relationships with her children which consistently underpin the parent-child boundaries that need to be drawn. One specific issue she resolved involved her 19-year-old son and his girlfriend who was pregnant with the group member's grandchild. By role playing the different positions that each of these people held in the home (the group member was paying the rent and had the right to set the rules, the girlfriend was feeling unaccepted by the group member and was acting out inappropriately, and the son was caught between trying to please the two females), the group member was able to clarify for herself how to approach future conflicts. A second member has improved her relationship with her youngest son (age 3) but still struggles with her 15-year-old daughter. What has been most effective for her was teaching her to count to 10 before responding to what she considers the goading of both of her children. In addition, she was feeling pressured by her mother, in whose house she lives, to have her son toilet trained.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

[Evaluation of side effects and complications during the treatment of affective psychoses with thymoleptics].

Evaluation of effects of amitriptyline, imipramine, maprotiline, mianserin , clomipramine and citalopram was performed in 84 patients (49 females and 35 males) age on average 40 years with diagnosis of affective psychosis treated in the Department of Psychiatry Medical School of Szczecin. Antidepressants independently from their pharmacological profile cause in above 50% of patients side effects mainly from autonomous nervous system. Tricyclic antidepressants caused some cardiotoxic effects which were not observed during administration of antidepressant drugs of different chemical structure, especially of citalopram. No effects on the haemopoietic system and on parenchymatous organs were observed. Neither were affected hypothalamic mechanisms for basal secretion of thyrotropic hormone, prolactin , cortisol and so ACTH. Multifactorial analysis of positive and untoward effects observed during the treatment shows comparable clinical value of all six evaluated drugs. A choice of a drug for an individual should depend on particular clinical contraindications.

Adult↗