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D Müller

Publications and source records attributed to D Müller.

At least 163 records · Page 9Linked to original sources
PubMed1998

Expression and synthesis of insulin-like growth factor-binding proteins in human glioma cell lines.

We previously demonstrated the presence of insulin-like growth factors (IGFs) and IGF-receptors in human glioma cell lines derived from primary glioblastomas. The biological action of IGFs is modulated by specific IGF-binding proteins (IGFBP)-1 to -7. By means of polymerase chain reaction (PCR), we detected mRNA transcripts for IGFBP-1 in 42%, IGFBP-2 in 65%, IGFBP-3 in 97%, IGFBP-4 in 3%, IGFBP-5 in 74%, IGFBP-6 in 94% and IGFBP-7 in 87% of the glioma cell lines. The specificity of the PCR reaction was verified by direct sequencing of the PCR product. In addition, the content of the most prevalent IGFBP-3 was measured in conditioned medium from glioma cells by specific radioimmunoassay with levels ranging from < 1 to 620 ng/ml. Moreover, the presence of membrane-bound IGFBPs (44, 50 and 60 kDa) as well as IGF-II receptors was demonstrated by using 125I-labelled IGF-II as a ligand. In conclusion, IGFBPs may modulate the IGF-mediated effects in these cell lines.

Aged↗
PubMed1998

PCR-based identification of clinically relevant Pseudallescheria/Scedosporium strains.

Pseudallescheria boydii (anamorph: Scedosporium apiospermum) and S. prolificans can cause severe infections in both the immunocompromized host and accidentally injured people. A species-specific polymerase chain reaction (PCR) enabling detection and discrimination of these fungi has not been available to date. In view of the difficult treatment especially of S. prolificans infections, a PCR-based detection system has been developed. Based on results of partial sequencing of ribosomal DNA, Scedosporium DNA could be amplified, either at the genus or at the species level. Hybridization probes for the identification of the PCR-products were established.

Base Sequence↗
PubMed1998

[Initial experiences with the Advanced Breast Biopsy Instrumentation (ABBI), a system for stereotactic excision of non-palpable breast lesions].

The advanced breast biopsy instrumentation (ABBI) allows the radiologically guided stereotactic excision of non-palpable radiodense lesions with high accuracy. Forty-six patients with suspicious clusters of microcalcifications (n = 37) and with round lesions (n = 9) of the breast were investigated using the ABBI. Tissue cylinders were successfully removed in 98% of cases. No wound complications occurred and cosmesis was excellent. Histopathology revealed 35 benign (76%) and 11 malignant (24%) lesions. With the ABBI system, non-palpable breast lesions can be precisely localized and excised.

Adult↗
PubMed1997

[10 years after Chernobyl--radioactivity of mother's milk-- measurements from Tirol, Tibet and Nepal].

10 years after the Chernobyl disaster gamma radioactivity from Cs-137 was determined in 53 breast milk samples from Tyrol, as well as 9 samples from Tibet and 2 from Nepal by means of a gamma-spectrometer with a germanium detector. In contrast to the values obtained within a few days, and again 1 year after the nuclear plant catastrophe, all samples from Tyrol showed gamma radioactivity levels (median 0.07 nCi/l; range 0.02-0.20 nCi/l) which were now below the limit laid down for baby food in Austria (0.3 nCi/l-11.1 Bq). The samples from Tibet and Nepal registered a slightly higher level of gamma radioactivity (median 0.16 nCi/l; range 0.16-0.41 nCi/l).

Animals↗
PubMed1997

Cdk2-dependent phosphorylation of p27 facilitates its Myc-induced release from cyclin E/cdk2 complexes.

Activation of Myc triggers a rapid induction of cyclin E/cdk2 kinase activity and degradation of p27. Overt degradation of p27 is preceded by a specific dissociation of p27 from cyclin E/cdk2, but not from cyclin D/cdk4 complexes. We now show that cyclin E/cdk2 phosphorylates p27 at a carboxy-terminal threonine residue (T187) in vitro; mutation of this residue to valine stabilises cyclin E/cdk2 complexes. This reaction is not significantly inhibited by high concentrations of p27, suggesting that cdk2 bound to p27 is catalytically active. In vivo, p27 bound to cyclins E and A, but not to D-type cyclins is phosphorylated. Myc-induced release of p27 from cdk2 requires cdk2 kinase activity and is delayed in a T187V mutant of p27. After induction of Myc, p27 phosphorylated at threonine 187 transiently accumulates in a non cdk2 bound form. Our data suggest a mechanism in which p27 is released from cyclin E/cdk2 upon phosphorylation; in Myc-transformed cells, release is efficient as phosphorylated p27 is transiently bound in a non-cdk2 containing complex and subsequently degraded.

Animals↗
PubMed1997

Monoclonal antibody against species-specific epitope of Pseudomonas aeruginosa Hsp60 protein cross-reacts with Pseudomonas stutzeri and other Pseudomonas species.

In a previous study, we determined the epitope of the Pseudomonas aeruginosa Hsp60 heat shock protein which is recognized by the specific monoclonal antibody (MAb) 2528. Subsequent investigations revealed a weak cross-reactivity of MAb 2528 with P. stutzeri, P. alcaligenes, P. mendocina and P. pseudoalcaligenes. To elucidate the molecular structure for these cross-reactions, we cloned the P. stutzeri hsp60 gene in Escherichia coli and determined the nucleotide sequence of the gene. In addition, the hsp60 gene of further Pseudomonas species was amplified and sequenced and amino acid substitutions within the epitope recognized by MAb 2528 were determined. The decapeptide QADIEARVLQ is unique to the P. aeruginosa Hsp60 protein, and cross-reaction of MAb 2528 reflects the phylogenetic relationship of Pseudomonas species as P. aeruginosa and all four cross-reacting species constitute a DNA homology group within the rRNA group I of the family Pseudomonadaceae, which belong to the gamma-subclass of the Proteobacteria.

Amino Acid Sequence↗
PubMed1997

Amyloid precursor protein in guinea pigs--complete cDNA sequence and alternative splicing.

We present the cDNA sequence of the guinea pig amyloid precursor protein comprising the complete coding sequence of 770 amino-acid residues. By alternative splicing of three exons transcripts encoding for 695, 714 and 751 amino acids and all forms previously denoted as L-APP are also generated. Guinea pig amyloid precursor protein was shown to exhibit extensive sequence similarity to its human and murine homologues of approx. 97% at the protein level which implies an evolutionary conserved but yet not fully understood physiological function.

Alternative Splicing↗
PubMed1997

New aspects of Leydig cell function.

Previous studies indicated that the Leydig cells of the human testes show similarities to neuroendocrine cells. In this context, the local synthesis of two neuroactive signaling molecules, namely nitric oxide (NO) and C-type natriuretic peptide (CNP), both acting via the second messenger, cyclic guanosine monophosphate (cGMP), might be of physiological relevance. By immunoblotting, immunohistochemical analyses and affinity crosslinking experiments, respectively, the presence of soluble guanylate cyclase (sGC), the NO receptor, and of guanylate cyclase B (GC-B), representing the CNP receptor, was demonstrated in Leydig cells, seminiferous tubules and blood vessels of the human testis. Moreover, cGMP and its binding protein cGMP-dependent protein kinase type I (GK I) were found in these structures. The functional activity of the two receptors was proved by generation of cGMP in response to treatments with the NO donor, sodium nitroprusside (SNP), and with CNP, respectively. As indicated by immunohistochemical analyses and by treatments of cells with either SNP or CNP, human Leydig tumour cells and MA10 cells, representing a mouse Leydig tumour cell line, were found to be distinguished by a reduced expression of the receptors for NO and CNP. Furthermore, expression levels of the components of the two cGMP-generating systems were found to be widely unchanged in Leydig cells during different ontogenetic stages. Though cGMP has been shown to influence testosterone release, the constant developmental expression patterns of NO and CNP apparently independent of differences in androgen production, the down-regulation of their receptors in tumorous cells, and the presence of GK I, may point to additional autocrine functions of these factors and of cGMP in Leydig cells. Moreover, possible paracrine actions of NO and CNP may include relaxation of seminiferous tubules and blood vessels in order to modulate sperm transport and testicular blood flow, respectively. These findings suggest that Leydig cell-derived factors may exert activities different from or in addition to those involved in the regulation of testosterone production.

Adult↗
PubMed1997

[Results of hip ultrasonographic screening in Austria].

The role of hip sonography in neonatal hip screening is still a controversial matter. This paper reports the results of the Austrian ultrasound hip screening program, in which all Austrian babies undergo hip sonography twice: at the birth clinic during the 1st week of life and at an age of 12-16 weeks. Data from all public health insurance companies since 1985 and all ICD data about children hospitalized because of CDH in Austria were collected and analyzed. The rate of sonographically pathological hips was 6.57% (1994). The treatment rate before introduction of hip sonography was 13.16% (1985). The rate of open reduction went down to 0.24 per 1000 newborns, including a high number of unscreened children born abroad and also children with teratological dislocation of the hip. Hip sonography screening proved to be effective in detecting true instability of the hip joint as well as dysplasia. The optimal time for sonographic screening does not seem to be immediately after birth when only "high risk" hips (clinical instability, positive family history, breech delivery) should undergo hip sonography, but at an age between 4 and 6 weeks when the hip has already shown its true nature. Since one sonographic scan appears to be sufficient for screening, a further reduction of costs could be accomplished. Disability owing to DDH can be avoided in a number of cases, and costs for conservative and surgical treatment as well as for later endoprostheses and early retirement can be economized.

Austria↗
PubMed1997

International study to compare antigen-specific methods used for the measurement of antiplatelet autoantibodies.

Platelet-associated and plasma autoantibodies against platelet glycoproteins (GP) have been demonstrated in patients with autoimmune thrombocytopenia (AITP) using various methods. Eight laboratories in seven countries participated in this international study to evaluate the interlaboratory agreement using glycoprotein-specific immunoassays for these autoantibodies. The participating laboratories received blind samples of frozen washed platelets and plasma from 22 normal donors and 22 AITP patients. Platelet-associated and plasma autoantibodies against GPIIb-IIIa and GPIb-IX were measured by MAIPA, immunobead assay or modified antigen capture assay. Of the control samples, 96.0% and 97.2% of all results for platelet-associated and plasma autoantibodies to GPIIb-IIIa/ GPIb-IX, respectively, were negative. The mean variation coefficient of the control samples of platelet-associated and plasma autoantibodies was 89.5% (range 11.1-272.9%) and 46.5% (range 21.0-78.0%), respectively. In 20/22 patient samples, platelet-associated autoantibodies to either glycoprotein were noted by at least two laboratories. The mean degree of agreement in these samples was 74.0%. There was a significant correlation in the individual antibody measurements between all laboratories (Kendall coefficient of concordance 0.60 and 0.38, P < 0.001; Spearman rank order test, range of correlation coefficient 52.3-94.0% and 42.2-85.0%, P < 0.05, for anti-GPIIb-IIIa and anti-GPIb-IX, respectively). In contrast, plasma autoantibodies to either glycoprotein were noted by at least two laboratories in only 13/22 patient samples. Moreover, the degree of agreement was poor (50.1%) and a significant correlation was noted between only six pairs of laboratories. We conclude that methods used in this study yield good interlaboratory agreement in measuring platelet-associated autoantibodies against GPIIb-IIIa and GPIb-IX. In contrast, poor agreement was found in detecting plasma autoantibodies to the same glycoproteins.

Autoantibodies↗
PubMed1997

Melatonin synthesis in the bovine pineal gland is regulated by type II cyclic AMP-dependent protein kinase.

We investigated the expression of regulatory (R) and catalytic (C) subunits of cyclic AMP-dependent protein kinase (cAK; ATP:protein phosphotransferase; EC 2.7.1.37) in the bovine pineal gland. In total RNA extracts of bovine pineal glands moderate levels of RI alpha/RII beta and high levels of C alpha and C beta mRNA were found. We were able to detect a strong signal for RII and C subunit at the protein level, whereas RI was apparently absent. Probing sections of the intact bovine pineal gland with RI and RII antibodies stained only RII in pinealocytes. Pairs of cyclic AMP analogues complementing each other in activation of type II cAK, but not cAKI-directed analogue pairs, showed synergistic stimulation of melatonin synthesis. Moreover, melatonin synthesis stimulated by the physiological activator norepinephrine in pineal cell cultures was inhibited by cAK antagonists. Taken together these results show the presence of RII regulatory and both C alpha and C beta catalytic subunits and thus cAKII holoenzyme in the bovine pineal gland. The almost complete inhibition of norepinephrine-mediated melatonin synthesis by the cAK antagonists emphasizes the dominant role of cyclic AMP as the second messenger and cAK as the transducer in bovine pineal signal transduction.

Animals↗
PubMed1997

[Increased liver density in computed tomography as a result of anti-arrhythmia therapy with amiodarone].

PURPOSE: To assess whether the hepatic density on CT scans of patients receiving amiodarone therapy differs significantly from the hepatic density of a control group not receiving the drug. METHODS: Hepatic density was assessed by CT in 31 patients receiving amiodarone, 7 receiving short-term (12-14 days), 8 receiving mid-term (20-89 days) and 16 receiving long-term therapy (3-26 months), as well as in a control group of 15 patients. RESULTS: Mean liver density of all patients under amiodarone therapy (77.9 +/- 11.7 HU) was significantly higher (p < 0.005) than in the control group (56.6 +/- 2.8 HU). The smallest increase in density was found in patients with short-term therapy (64.8 +/- 3.4 HU; p < 0.05), the greatest increase in patients with long-term therapy (85.0 +/- 8.9 HU; p < 0.001). CONCLUSION: In patients receiving amiodarone therapy, a significantly increased hepatic density on CT scans is observed. This finding has to be considered as a differential diagnosis to other hepatopathies with increased density of the liver.

Adult↗
PubMed1997

[Results of a contrast-medium supported 3D MR-angiography in respiratory arrest following optimization of contrast medium bolus].

PURPOSE: Reduction of the contrast material volume by optimised bolus administration during a breath-hold 3D MR angiography and its clinical value. MATERIALS AND METHODS: Breath-hold ultrafast 3D gadolinium-enhanced MR angiography (TR 5 ms, TE 2 ms, FA 20 degrees) of the thoracic and abdominal aorta was performed in 50 patients and correlated with an i.a. DSA. 25 patients (group 1) were examined with a contrast material volume of 40 ml Gd-DTPA and three successive acquisitions at fixed intervals (25, 53 and 81 s) after start of the contrast material injection. Another group of 25 patients (group 2) received only 20 ml Gd-DTPA and the start of the MR acquisition was determined individually by prior evaluation of the contrast material transit times after injection of a test bolus. The signal-to-noise (S/N) and contrast-to-noise (C/N) ratios were compared and a subjective image quality rating (0-3) by three reviewers was achieved in both groups. RESULTS: A total of 37 vascular pathologies were correctly detected by MR angiography compared to i.a. DSA. The grading of stenoses was overestimated in some cases. The S/N and C/N were higher in group 2 (63.2 and 50.1) than in group 1 (58.0 and 38.9). The subjective ratings also showed better results in group 2 (2.76) than in group 1 (2.20). CONCLUSION: The ultrafast gadolinium-enhanced 3D MR angiography allowed a reliable visualisation of the thoracic and abdominal aorta and its branches in a single breath-hold. An optimised examination with a reduced contrast material volume can be achieved by an individual adaptation of the MR acquisition to contrast material administration after measurement of the contrast material transit times.

Aged↗