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Biomedical subjects

S Müller

Publications and source records attributed to S Müller.

At least 37 records · Page 2Linked to original sources

Zoo-FISH in the European mole (Talpa europaea) detects all ancestral Boreo-Eutherian human homologous chromosome associations.

Zoo-FISH with human whole-chromosome paint probes delineated syntenic association of human homologous chromosome segments 3-21, 14-15, 16-19, 4-8, 7-16 and 12-22 (twice) in the European mole (Talpa europaea, Talpidae, Eulipotyphla, Mammalia). These segment associations represent shared ancestral Boreo-Eutherian traits, half of which were previously not described for Eulipotyphla. The karyotype of the European mole acquired a minimum of 19 translocations and six inversions compared to the presumed Boreo-Eutherian ancestor.

Animals↗

Standardized exchange of clinical documents--towards a shared care paradigm in glaucoma treatment.

OBJECTIVES: The exchange of medical data from research and clinical routine across institutional borders is essential to establish an integrated healthcare platform. In this project we want to realize the standardized exchange of medical data between different healthcare institutions to implement an integrated and interoperable information system supporting clinical treatment and research of glaucoma. METHODS: The central point of our concept is a standardized communication model based on the Clinical Document Architecture (CDA). Further, a communication concept between different health care institutions applying the developed document model has been defined. RESULTS: With our project we have been able to prove that standardized communication between an Electronic Medical Record (EMR), an Electronic Health Record (EHR) and the Erlanger Glaucoma Register (EGR) based on the established conceptual models, which rely on CDA rel.1 level 1 and SCIPHOX, could be implemented. The HL7-tool-based deduction of a suitable CDA rel.2 compliant schema showed significant differences when compared with the manually created schema. Finally fundamental requirements, which have to be implemented for an integrated health care platform, have been identified. CONCLUSIONS: An interoperable information system can enhance both clinical treatment and research projects. By automatically transferring screening findings from a glaucoma research project to the electronic medical record of our ophthalmology clinic, clinicians could benefit from the availability of a longitudinal patient record. The CDA as a standard for exchanging clinical documents has demonstrated its potential to enhance interoperability within a future shared care paradigm.

Computer Communication Networks↗

Mutational and functional analyses of xylosyltransferases and their implication in osteoarthritis.

OBJECTIVE: The hallmark in osteoarthritis (OA) is the loss of proteoglycans (PGs) in articular cartilage (AC). Xylosyltransferase I (XT-I) catalyzes the transfer of xylose to serine residues in the core protein and initiates the biosynthesis of PGs in AC. The XYLT-II gene encodes a highly homologous protein but its biological function is not yet known. Here we investigate for the first time genetic variations in the XYLT-genes and serum XT-I activities and their implication in OA. METHODS: Denaturing high-performance liquid chromatography (DHPLC) was used for the screening of the XYLT-genes in 49 OA patients. For a detailed characterization of XT-I amino acid exchanges we performed recombinant expression of XT-I mutants in insect cells. Furthermore, the XT activity was measured in the patients' serum. RESULTS: The variation c.1569C>T (XYLT-II) occurs with a significantly higher frequency in younger OA patients in comparison with the older ones (P<0.001) and the controls (P<0.02). Furthermore, significantly higher serum XT activities were found in patients with a long disease duration of OA (P<0.04). The recombinant XT-I mutants p.P385L and p.I552S had reduced enzymatic activity (85% and 74%) compared with the wildtype (wt). CONCLUSIONS: Our findings indicate a correlation of the c.1569 T-allele in XYLT-II with an earlier manifestation of OA and that the serum XT activity is a potential biochemical marker for staging and monitoring the progression of AC damage in OA. Comparison of XT-I activity in mutant enzymes in vivo and in vitro revealed that heterozygous mutations are not involved in OA.

Aged↗

[Stable tachycardia with wide QRS complex in pre-hospital emergency medicine].

BACKGROUND: Sustained, stable wide QRS-complex tachycardia (WCT) remains a diagnostic challenge, because the treatment of supra-ventricular tachycardia (SVT) with aberrant conduction differs considerably from that of a ventricular tachycardia (VT). A usual recommendation for treating a case of a stable WCT is to manage it as if it were VT, in accordance with the consideration of "first do no harm". The aim of this study was to determine whether Board-certified emergency-physicians are able to differentiate VT from SVT with aberrant conduction in a high percentage of cases (> 90%), thus to assure more precise prehospital treatment." METHODS: Eight electrocardiograms with WCT (four with electrophysiologically proven VT or SVT, respectively) were evaluated in a blinded fashion by 64 Board-certified emergency-physicians (23 female, 41 male, mean age: 37,8 + 5,1 years). Initially, the diagnosis had to be made without any further information. Afterwards the same electrocardiograms were presented again, providing important additional information. RESULTS: 55% of the study population were able to establish the correct diagnosis merely by evaluating the electrocardiogram. Providing the above mentioned additional information, the number of correct diagnoses increased to 61%. These results were roughly similar in all subgroups, only the subgroup of cardiologists showed a trend to better results with correct diagnoses in 68% without and 73 % with additional information. None of the subgroups reached the pre-specified cut-off of > or = 90% correct diagnoses. Specialist status as well as experience in emergency medicine had no significant influence on the results, only the subgroup of emergency physicians with an experience of more than five years showed a trend towards a higher rate of correct diagnosis, compared with the subgroup with less than one year experience in emergency medicine. CONCLUSION: In cases of stable WCT the evaluation of the electrocardiogram without further information in prehospital emergency-medicine leads to unsatisfactory results. The correct diagnosis in WCT can be improved by using additional data but the diagnostic accuracy is still low. Therefore, the differential diagnosis of stable WCT in preclinical emergency-medicine cannot be recommended. Until proven otherwise, any stable WCT should be managed as if it were VT.

Adult↗

Reversible impaired memory induced by pulsed methylprednisolone in patients with MS.

Thirty patients with multiple sclerosis were randomized to 500 or 2,000 mg of methylprednisolone (MP) over 5 days. They were prospectively studied neuropsychologically before and at days 6 and 60 after onset of the therapy, using a double-blind study design. Patients showed selective deterioration of declarative memory retrieval at day 6, which was fully reversible at day 60. Although the sample size was small, these effects were independent of the administered MP dose.

Adolescent↗

The bisphosphonate ibandronate improves implant integration in osteopenic ovariectomized rats.

Osteoporosis is known to impair the process of implant osseointegration. Bisphosphonates are drugs that inhibit osteoclast-mediated bone resorption and normalize the high rate of bone turnover that characterizes this disease. Consequently, there is a rationale for using bisphosphonates to enhance the early stabilization of implants in subjects with low bone mass. In this study, 84 rats received titanium-only or hydroxyapatite (HA)-coated titanium femoral implants, 3 months after being ovariectomized (OVX) or sham operated. They were then treated for 4 weeks. The OVX rats were randomly assigned to daily subcutaneous injections of either saline or the bisphosphonate ibandronate (at a dose of 1 microg/kg or 25 microg/kg), while the sham-operated animals received saline throughout. The 1 microg/kg or 25 microg/kg ibandronate doses are considered translatable to doses used to treat osteoporosis and metastatic bone disease (MBD), respectively, in rats, and roughly reflect those used in humans. At the end of the treatment period, bone mineral density (BMD) at the lumbar spine increased in both of the ibandronate-treated groups when compared with the OVX control animals and to a level similar to that of the sham-operated control group. Osseointegration, determined by histomorphometric analysis and expressed as percentage of osseointegration implant surface (OIS), did not differ between groups for the titanium-only implants. For the HA-coated implants, however, OIS was 113.5% and 185% higher in the groups receiving 1 microg/kg or 25 microg/kg ibandronate, respectively, relative to the OVX controls. In turn, the OIS of the HA-coated implants was 56.5% lower in the OVX control group than in the sham control group. These findings clearly demonstrate that OVX-induced osteopenia impairs the osseointegration of HA-coated titanium implants and that ibandronate, administered at doses analogous to those used to clinically treat osteoporosis and MBD, counters this harmful effect. Ibandronate may, therefore, have a role in improving the osseointegration of implants in patients with osteoporosis and MBD.

Animals↗

High efficacy of gemcitabine and cisplatin plus trastuzumab in patients with HER2-overexpressing metastatic breast cancer: a phase II study.

AIMS: Effective and tolerable regimens are sought specifically in women who have been pre-treated with anthracyclines and taxanes. Gemcitabine and cisplatin plus trastuzumab has shown synergistic activity in vitro, and provides a new mechanism of drug interaction. This multicentre phase II study aimed to evaluate the efficacy and tolerability of gemcitabine and cisplatin plus trastuzumab in previously treated patients with metastatic breast cancer (MBC). MATERIALS AND METHODS: Previously treated patients with human epidermal growth factor receptor 2 (HER2) overexpressing MBC were enrolled in a multicentre phase II study (DAKO Hercep Test 3+). Treatment consisted of gemcitabine (750 mg/m2), cisplatin (30 mg/m2) given on days 1 and 8 every 3 weeks, and trastuzumab (4 mg/kg loading dose, 2 mg/kg weekly). RESULTS: Twenty patients were recruited, all of whom had previously received chemotherapy (12 pre-treated with taxanes, 18 pre-treated with anthracyclines seven pre-treated with taxanes and trastuzumab). A median of six cycles of the study treatment was delivered. There were eight partial responses, for an overall response rate of 40% (95% confidence interval 16.5-63.5%). The clinical benefit rate (complete response plus partial response plus stable disease) was 80% (95% CI 54.2-95.8%). The response rate in patients who had already received a trastuzumab-based regimen for MBC was 57.1% (95% CI 7.7-100%). Median time to progression was 10.2 months, and median overall survival was 18.8 months. Main toxicities were leukopenia (grade 3 in 55% of patients) and thrombocytopenia (grade 3 in 35% and grade 4 in 5% of patients). Non-haematological toxicity was rarely severe. CONCLUSIONS: Combination chemotherapy with gemcitabine and cisplatin plus trastuzumab is well tolerated and active in patients with HER2 overexpressing MBC, even after prior exposure to anthracyclines and taxanes.

Adult↗

Plasmodium falciparum possesses organelle-specific alpha-keto acid dehydrogenase complexes and lipoylation pathways.

The human malaria parasite Plasmodium falciparum possesses a single mitochondrion and a plastid-like organelle called the apicoplast. Both organelles contain members of the KADH (alpha-keto acid dehydrogenase) complexes--multienzyme complexes that are involved in intermediate metabolism. In the asexual blood stage forms of the parasites, the alpha-ketoglutarate dehydrogenase and branched chain KADH complexes are both located in the mitochondrion, whereas the pyruvate dehydrogenase is exclusively found in the apicoplast. In agreement with this distribution, Plasmodium parasites have two separate and organelle-specific pathways that guarantee lipoylation of the KADH complexes in both organelles. A biosynthetic pathway comprised of lipoic acid synthase and lipoyl (octanoyl)-ACP:protein Nepsilon-lipoyltransferase B is present in the apicoplast, whereas the mitochondrion is supplied with exogenous lipoic acid, and ligation of the metabolite to the KADH complexes is accomplished by a lipoate protein ligase A similar to that of bacteria and plants. Both pathways are excellent potential targets for the design of new antimalarial drugs.

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗

Phylogenetic inferences of Atelinae (Platyrrhini) based on multi-directional chromosome painting in Brachyteles arachnoides, Ateles paniscus paniscus and Ateles b. marginatus.

We performed multi-directional chromosome painting in a comparative cytogenetic study of the three Atelinae species Brachyteles arachnoides, Ateles paniscus paniscus and Ateles belzebuth marginatus, in order to reconstruct phylogenetic relationships within this Platyrrhini subfamily. Comparative chromosome maps between these species were established by multi-color fluorescence in situ hybridization (FISH) employing human, Saguinus oedipus and Lagothrix lagothricha chromosome-specific probes. The three species included in this study and four previously analyzed species from all four Atelinae genera were subjected to a phylogenetic analysis on the basis of a data matrix comprised of 82 discrete chromosome characters. The results confirmed that Atelinae represent a monophyletic clade with a putative ancestral karyotype of 2n = 62 chromosomes. Phylogenetic analysis revealed an evolutionary branching sequence [Alouatta [Brachyteles [Lagothrix and Ateles]]] in Atelinae and [Ateles belzebuth marginatus [Ateles paniscus paniscus [Ateles belzebuth hybridus and Ateles geoffroyi]]] in genus Ateles. The chromosomal data support a re-evaluation of the taxonomic status of Ateles b. hybridus.

Animals↗

Investigation of marmoset hybrids (Cebuella pygmaea x Callithrix jacchus) and related Callitrichinae (Platyrrhini) by cross-species chromosome painting and comparative genomic hybridization.

We report on the cytogenetics of twin offspring from an interspecies cross in marmosets (Callitrichinae, Platyrrhini), resulting from a pairing between a female Common marmoset (Callithrix jacchus, 2n = 46) and a male Pygmy marmoset (Cebuella pygmaea, 2n = 44). We analyzed their karyotypes by multi-directional chromosome painting employing human, Saguinus oedipus and Lagothrix lagothricha chromosome-specific probes. Both hybrid individuals had a karyotype with a diploid chromosome number of 2n = 45. As a complementary tool, interspecies comparative genomic hybridization (iCGH) was performed in order to screen for genomic imbalances between the hybrids and their parental species, and between Callithrix argentata and S. oedipus, respectively. These genomic imbalances were confined to centromeric and telomeric heterochromatin, while euchromatic chromosome regions appeared balanced in all species investigated. When comparing marmosets and tamarins, sequence divergence of centromeric heterochromatin was already clearly noticeable. In the C. argentata and C. pygmaea genomes numerous subtelomeric regions were affected by amplification of different repetitive sequences. Cross-species FISH with a microdissection-derived C. pygmaea repetitive probe revealed species specificity of this repetitive sequence at the molecular cytogenetic level of resolution.

Animals↗

Reversible H-induced switching of the magnetic easy axis in Ni/Cu(001) thin films.

A reversible switching of the easy axis of magnetization for Ni on Cu(001) from in plane to out of plane is found by changing the partial pressure of hydrogen in the gas phase around the sample, allowing even for oscillations of the magnetization direction. A quantitative low-energy electron diffraction study of the diffracted intensity versus electron energy [I(E)] shows that the hydrogen-induced spin reorientation transition is accompanied by changes of the tetragonal distortion of the topmost Ni layer upon hydrogen adsorption. Surprisingly, the orientation switch to perpendicular to the surface comes with a relaxation, i.e., reduction of the film's tetragonal distortion rather than its amplification.

Journal Article↗

Use of endoscopy and renal biopsy for the diagnosis of kidney disease in free-living birds of prey and owls.

Eighty-nine free-living birds of prey and owls were examined and blood samples and radiographs were taken. In addition, 126 specimens of renal tissue were obtained without complications, with a mean postbiopsy haemorrhage time of 67 seconds. On average, the samples were 2.2 mm long, 1.3 mm wide and 1.0 mm deep and they all contained proximal and distal tubuli and from one to 89 glomeruli; 49 of them contained from one to four intralobular veins, and on average each sample contained 10.7 per cent air sac tissue; 113 of the 126 samples could be evaluated histologically.

Animals↗

Hemolytic uremic syndrome following prolonged gemcitabine therapy: report of four cases from a single institution.

Hemolytic uremic syndrome (HUS) has been described following the administration of multiple antineoplastic agents, most notably mitomycin C. More recently, several cases of gemcitabine-induced HUS have been observed with the overall incidence of gemcitabine-induced HUS estimated at 0.015-0.25%. We here report on four patients who developed HUS following gemcitabine therapy at our institution within the last year (incidence 1.4%). All these patients had advanced-stage disease, were heavily pretreated, and received prolonged gemcitabine application, suggesting that in this subgroup of patients HUS may be more frequently encountered than documented so far.

Adenocarcinoma↗

[Current views on the prevention of ailments of the musculoskeletal system through muscle strengthening programs].

Because of an increasingly older population structure and the enhanced relevance of body composition, the prevention of problems arising from the musculoskeletal system has become of central importance. Strengthening and muscle-building training have been proven to be useful even for older people. The training is focused on the types of movement and exertion that frequently occur in the "activities of daily living." In addition, a purely hypertrophic training for building muscle mass must be differentiated from a more sensorimotor oriented training with situational employment of the muscles for optimizing motor control and coordination. There are no contraindications for strength training when the program is adapted to the individual. The rate of injury is small, even for people at low performance levels.

Accidental Falls↗

First-principles-based surface phase diagram of fully relaxed binary alloy surfaces.

The combination of density-functional theory (DFT) calculations of geometrically fully relaxed binary alloy surfaces with concepts from statistical physics is applied to construct a DFT-based phase diagram for a binary alloy surface. As a first example, we studied the appearance of Co antisite atoms at CoAl(100) surfaces. The structural parameters as multilayer relaxations, surface buckling, lateral order, and segregation profile of the predicted stable surface phases are in excellent agreement with experimental structure determinations applying low-energy electron diffraction.

Journal Article↗

Bovine aortic endothelial cells are susceptible to Hantaan virus infection.

Hantavirus serotype Hantaan (HTN) is one of the causative agents of hemorrhagic fever with renal syndrome (HFRS, lethality up to 10%). The natural host of HTN is Apodemus agrarius. Recent studies have shown that domestic animals like cattle are sporadically seropositive for hantaviruses. In the present study, the susceptibility of bovine aortic endothelial cells (BAEC) expressing alpha(V)beta(3)-integrin to a HTN infection was investigated. Viral nucleocapsid protein and genomic RNA segments were detected in infected BAEC by indirect immunofluorescence assay, Western blot analysis, and reverse transcription-polymerase chain reaction (RT-PCR), respectively. The results of this study strongly support our previous observation on Puumala virus (PUU) that has been propagated efficiently in BAEC. These findings open a new window to contemplate the ecology of hantavirus infection and transmission route from animal to man.

Animals↗

Bovine aortic endothelial cells are susceptible to hantavirus infection; a new aspect in hantavirus ecology.

Hantaviruses are enveloped RNA viruses that belong to the family Bunyaviridae. They are the causative agents of hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). Hantaviruses show a worldwide distribution with specific rodent species as natural hosts. It is known that rodents can transmit the virus via feces, urine, saliva, or bites to humans. Additionally, antibodies against different hantaviruses were also found in domestic animals, For example, Danes et al. documented hantavirus-specific IgG titers in 2% of examined cattle [Ceskoslov. Epidemiol. Mikrobiol. Imunol. 41 (1992) 15]. In order to clarify the possibility of a nonrodent and nonhuman hantavirus infection, the susceptibility of bovine aortic endothelial cells (BAEC) to Hantavirus serotype Puumala infection was investigated. The hantaviral nucleocapsid protein was detected in 95% of infected BAEC at the fourth cell culture passage 12 weeks after initial infection by immunofluorescence assay (IFA). The presence of Puumala virus (PUU) nucleocapsid protein and the viral glycoproteins G1 and G2 in infected cells were additionally confirmed by Western blot analysis. The viral RNA genome was identified in infected BAEC cultures and in cell-free culture medium at the fourth passage by reverse transcription polymerase chain reaction (RT-PCR), verified by cDNA nucleotide sequence analysis, showing a 98-100% homology to the input virus. The infected BAEC cultures were shown to express alpha(V)beta(3)-integrin surface receptors that are known to mediate virus entry in human cells and revealed no major cytopathic effects (CPEs) as assayed by immunofluorescence staining of the cytoskeletal components actin and microtubules. In the present study, we documented for the first time that a nonrodent and nonhuman aortic endothelial cell culture of bovine origin (BAEC) can be efficiently infected with a hantavirus. This finding is of particular importance because it adds new aspects to questions dealing with host species barrier, viral reservoir, virus transmission, and ecology of hantaviruses.

Animals↗