Biomedical subjects

Elisabeth Müller

Publications and source records attributed to Elisabeth Müller.

6 recordsLinked to original sources

PubMed2005

Cytogenetic instability in young patients with multiple primary cancers.

Patients younger than 45 years with multiple cancers and a family history of cancer were identified and examined for cytogenetic instability. The cohort included 50 individuals: 19 patients suffering from at least 2 independent cancers, 11 healthy control individuals, a positive control group of 5 highly radiosensitive patients (>grade 3, RTOG), and a tumor control group of 15 patients with a single tumor. Peripheral blood lymphocytes were irradiated in vitro (0.7 Gy, 2.0 Gy). Metaphase chromosomes 1, 2, and 4 were labeled by means of 3-color fluorescence in situ hybridization. Chromosomal aberrations (breaks per metaphase [B/M], complex chromosomal rearrangements [CCR/M]) were analyzed. Very high levels of chromosomal aberrations were detected in a "core group" of 5 patients. These patients displayed much higher rates of B/M and CCR/M than controls. Ten patients had moderately elevated chromosomal aberrations and 4 patients were indistinguishable from controls. We conclude that a significant proportion of young patients with multiple tumors and a family background of cancer display cytogenetic instability.

Adult↗

PubMed2005

Optically bright quantum dots in single Nanowires.

We fabricate and demonstrate optically active quantum dots embedded in single nanowires. Observation of photon antibunching proves the zero dimensionality of these heterostructures that can be epitaxially grown on various substrates, including silicon. We show that the nanowire dots are intense single photon sources, typically an order of magnitude brighter than self-assembled quantum dots. Due to control over their composition, size, and position, nanowire dots are ideal building blocks for fully controlled quantum dot molecules.

Electric Wiring↗

PubMed2005

Transcript profiles of Blumeria graminis development during infection reveal a cluster of genes that are potential virulence determinants.

High-density cDNA microarrays (2,027 unigenes) were used to analyze transcript profiles of the plant-pathogenic fungus Blumeria graminis f. sp. hordei throughout its asexual life cycle and development of infection. RNA was obtained from four stages preceding penetration and four stages after penetration of the host cells. The microarray data was validated by comparing the expression of a plasma membrane H+-ATPase and fructose-1,6-bis phosphatase with the data obtained from a quantitative polymerase chain reaction (PCR) assay. The results showed that there was a global switch in expression between the pre- and postpenetrative stages. This was largely due to accumulation of RNA encoding protein biosynthesis genes in the late stages. Other functional clusters, such as virulence-related genes and sterol metabolism genes, are up-regulated in pre- and postpenetration stages, respectively. A group of RNAs whose abundance correlated with the expression of cap20, a gene known to be required for virulence in Colletotrichum gloeosporioides, identified genes that are strong candidates for pathogenicity factors in B. graminis.

Ascomycota↗

PubMed2004

Impact of various parameters in detecting chromosomal aberrations by FISH to describe radiosensitivity.

BACKGROUND AND PURPOSE: Analysis of radiation-induced chromosomal aberrations is regarded as the "gold standard" for classifying individual radiosensitivity. A variety of different parameters can be used. The crucial question, however, is to explore which parameter is suited best to describe the differences between patients with increased radiosensitivity and healthy individuals. PATIENTS AND METHODS: In this study, five patients with severe radiation-induced late effects of at least grade 3, classified according to the Radiation Therapy Oncology Group (RTOG), and eleven healthy individuals were examined retrospectively. Peripheral blood lymphocytes were irradiated in vitro with 0.7 Gy and 2.0 Gy prior to cultivation and stained by means of three-color fluorescence in situ hybridization (FISH). The detailed analysis was focused on the number of breaks per metaphase, on breaks from complex chromosomal rearrangements per metaphase, as well as on the percentage of translocations, dicentric chromosomes, breaks, and excess acentric fragments-each in comparison with the total number of mitoses analyzed. RESULTS: Using the number of breaks from complex chromosomal rearrangements after 2.0 Gy, radiosensitive patients as endpoint were clearly to be distinguished (p = 0.001) from healthy individuals. Translocations (p = 0.001) as well as breaks per metaphase (p = 0.002) were also suitable indicators for detecting differences between patients and healthy individuals. The parameters "percentage of dicentric chromosomes", "breaks", and "excess acentric fragments" in comparison to the total number of mitoses analyzed could neither serve as meaningful nor as significant criteria, since they showed a strong interindividual variability. CONCLUSION: To detect a difference in chromosomal aberrations between healthy and radiosensitive individuals, the parameters "frequency of breaks per metaphase", "complex chromosomal rearrangements", and "translocations" are most suitable.

Adult↗

PubMed2002

Population changes in a biofilm reactor for phosphorus removal as evidenced by the use of FISH.

Induction of denitrification was investigated for a lab-scale phosphate removing biofilm reactor where oxygen was replaced with nitrate as the electron acceptor. Acetate was used as the carbon source. The original biofilm (acclimatised with oxygen) was taken from a well-established large-scale reactor. During the first run, a decrease in the denitrifying bio-P activity was observed after 1 month following a change in the anaerobic phase length. This was initially interpreted as a shift in the microbial population caused by the changed operation. In the second run, biomass samples were regularly collected and analysed by fluorescent in situ hybridisation (FISH) and confocal laser scanning microscopy (CLSM). Concurrently, samples were taken from the original reactor with oxygen as electron acceptor in order to investigate natural microbial fluctuations. A similar decrease in the activity as in the first run was seen after one month, although the phase lengths had not been varied. Hence, the decrease after 1 month in the first and second run should be seen as a start-up phenomenon. FISH could detect a noticeable shift in the microbial population mainly within the first 2 weeks of operation. Almost all bacteria belonging to the alpha subclass disappeared and characteristic clusters of the beta and gamma subclasses were lost. Small clusters of gram-positive bacteria with a high DNA G + C content (GPBHGC) were gradually replaced by filamentous GPBHGC. Most of the bacteria in the denitrifying, phosphate removing biofilm belonged to the beta subclass of Proteobacteria. The applied set of gene probes had been selected based on existing literature on biological phosphate removing organisms and included a recently published probe for a Rhodocyclus-like clone. However, none of the specific probes hybridised to the dominant bacterial groups in the reactors investigated. No noticeable changes were detected in the aerobic bench-scale reactor during this period, indicating that the observed changes in the lab-scale reactor were caused by the changed environment.

Acetates↗

PubMed2002

Blunt renal trauma in children: 26 years clinical experience in an alpine region.

OBJECTIVES: From 1975 to 2001, 254 children aged younger than 17 were transferred to our department for renal trauma. We performed a retrospective study to assess causality and kind of the trauma, diagnostic procedures and therapeutic consequences, respectively. METHODS: The 254 children at a mean age of 10.56 years (+/-3.8) ranging from 2 to 17 years were treated for kidney trauma. Among these, 166 presented with a grade I trauma according to the kidney injury scale of the American Association for the Surgery of Trauma without any other accompanying injuries and 88 had a grade II-V lesion, respectively. Diagnostic evaluation included various standard lab tests such as urinalysis and routine blood parameters, ultrasound, IVP and/or CT. RESULTS: Most of the traumatic injuries resulted from skiing accidents. However, 18 children had a severe polytrauma with laceration of other vital organs. Most of the renal injuries could be treated conservatively. Surgical treatment options included immediate exploration, reconstruction, partial resection, or even nephrectomy. No child died. CONCLUSIONS: Due to leisure time activities in our region, skiing accidents often result in isolated laceration of the kidney. About one third presented with a severe kidney trauma, and approximately 20% of all affected children required surgical therapy. However, most of the injured kidneys could be preserved and only four nephrectomies had to be performed.

Accidental Falls↗