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Biomedical subjects

U Scholz

Publications and source records attributed to U Scholz.

At least 19 recordsLinked to original sources

CR-EST: a resource for crop ESTs.

The crop expressed sequence tag database, CR-EST (http://pgrc.ipk-gatersleben.de/cr-est/), is a publicly available online resource providing access to sequence, classification, clustering and annotation data of crop EST projects. CR-EST currently holds more than 200,000 sequences derived from 41 cDNA libraries of four species: barley, wheat, pea and potato. The barley section comprises approximately one-third of all publicly available ESTs. CR-EST deploys an automatic EST preparation pipeline that includes the identification of chimeric clones in order to transparently display the data quality. Sequences are clustered in species-specific projects to currently generate a non-redundant set of approximately 22,600 consensus sequences and approximately 17,200 singletons, which form the basis of the provided set of unigenes. A web application allows the user to compute BLAST alignments of query sequences against the CR-EST database, query data from Gene Ontology and metabolic pathway annotations and query sequence similarities from stored BLAST results. CR-EST also features interactive JAVA-based tools, allowing the visualization of open reading frames and the explorative analysis of Gene Ontology mappings applied to ESTs.

Crops, Agricultural↗

Molecular mapping of resistance to Fusarium head blight in the spring wheat cultivar Frontana.

Fusarium head blight (FHB) is a destructive disease of wheat. The objective of this study was to characterise the FHB resistance of the Brazilian spring wheat cultivar Frontana through molecular mapping. A population of 210 doubled-haploid lines from a cross of Frontana (partially resistant) and Remus (susceptible) was evaluated for FHB resistance during three seasons. Spray and single-spikelet inoculations were applied. The severity, incidence and spread of the disease were assessed by visual scoring. The population was genotyped with 566 DNA markers. The major QTL effect associated with FHB resistance mapped to chromosome 3A near the centromere, explaining 16% of the phenotypic variation for disease severity over 3 years. The most likely position is in the Xgwm720-Xdupw227 interval. The genomic region on 3A was significantly associated with FHB severity and incidence in all years evaluated, but not with FHB spread, indicating the prominent contribution of this QTL to resistance against initial infection. The map interval Xgwm129-Xbarc197 on chromosome 5A also showed consistent association with FHB severity and accounted for 9% of the phenotypic variation. In addition, smaller effects for FHB severity were identified on chromosomes 1B, 2A, 2B, 4B, 5A and 6B in single years. Individual QTLs for resistance to FHB spread accounted for less than 10% of the variation in trait expression. The present study indicates that FHB resistance of Frontana primarily inhibits fungal penetration (type I resistance), but has a minor effect on fungal spread after infection (type II resistance).

Analysis of Variance↗

Contact lens induced keratitis associated with contact lens wear.

PURPOSE: To evaluate clinical characteristics, risk factors, management and outcome of contact lens induced keratitis (CLIK) associated with contact lens wear. METHODS: The study comprised all consecutive patients presenting with contact lens related presumed microbial keratitis during a 12-month period at our department. Detailed demographic data, type of contact lens, duration of lens wear, wearing schedule and lens hygiene were derived from a self-administered questionnaire. Severity of ulcer, corneal scrapings, treatment and final outcome were evaluated. RESULTS: 27 patients with CLIK, some of which may have been sterile peripheral infiltrates, due to contact lens wear were detected. In the majority of the cases patients had used disposable soft contact lenses (89%) and most of them had a daily wearing schedule (78%). 51.8% patients cleaned their lenses regularly. 6 (22%) applied no disinfection since their lenses were disposable on removal. In 3 of our cases with CLIK, penetrating keratoplasty had to be performed. CONCLUSION: Disposable contact lenses seem to have been a predisposing factor for contact lens induced keratitis also when used on a daily wear schedule. Insufficient contact lens care products and/or manufacturing characteristics may be responsible for CLIK, which is also observed in otherwise compliant contact lens users. In 3 of our patients with CLIK keratoplasty became necessary, indicating that contact lens induced keratitis may result in severe corneal complications.

Adult↗

Information system for the support of research, diagnosis and therapy of inborn metabolic diseases.

We developed an information system for inborn metabolic diseases. The system consists of three parts. The first part is the MD-Cave for information on laboratory findings, genes, enzymes and metabolic pathways. The second part (ASDB) concerns with active agents and their different mechanisms of action inside the metabolic pathway and possible therapeutic treatment of these illnesses. The third part deals with the integration of these and other data bases for easy access to different information. This information system can be helpful for scientists and physicians working in the field of inborn metabolic diseases.

Biochemical Phenomena↗

RAMEDIS- rare metabolic diseases publishing tool for genotype-phenotype correlation.

To gain further knowledge about rare genetic diseases, a world wide method for data collection via the Internet has been established. This new approach will improve collecting valuable data from single case reports. RAMEDIS saves standardised patient data which will be usable for statistics, longitudinal examinations and co-operative studies in future time. Embedded in the scene of the German Human Genome Project, RAMEDIS directly will enable phenotype-genotype correlation's. Technically RAMEDIS is based on the Oracle database management system with some additional tools. Since November 2000 first case reports are committed online. Beside the better characterisation of clinical heterogeneity of rare diseases, there may be a great benefit for the treatment of these patients in whom prospective studies are otherwise expensive and difficult to perform. Quality of clinical diagnostic process and therapy will increase.

Computational Biology↗

Quantification of sensory trick impact on tremor amplitude and frequency in 60 patients with head tremor.

Head tremor with an obvious head deviation is the typical clinical picture of tremulous cervical dystonia (TCD), whereas head tremor without any significant head deviation allows for the differential diagnosis of dystonic head tremor (DHT) as well as essential head tremor (EHT). Clinical and polyelectromyographic (poly-EMG) studies have shown a suppression of dystonic muscle activity in patients with TCD performing a maneuver called geste antagonistique. The effect of these trick maneuvers on head tremor has not been investigated in patients with DHT and EHT. We studied the impact of sensory trick maneuvers on head tremor amplitude and frequency clinically by using the tremor subscore of the Tsui scale and by means of computer-based accelerometry in 60 patients with head tremor as their major disorder. Based on clinical data (modified Tsui scale: rating of spontaneous head deviation [rotation + lateroflexion + ante-/retroflexion]), pharmacologic response of tremor (propranolol, primidone, or alcohol), family history (postural hand tremor in first-degree relatives), and poly-EMG findings (reciprocal inhibition in neck muscles during voluntary head rotation), 34 patients were diagnosed as having TCD, 14 were classified as having DHT, and 12 patients were diagnosed as having EHT. Using a clinical rating scale, head tremor amplitudes showed a significant decrease compared with baseline during the performance of sensory trick maneuvers in patients with TCD and DHT, but not in patients with EHT. This clinically observed effect was accompanied by a significant reduction in the mean peak power of the dominant frequency in patients with TCD (decrease by 83%, p = 0.0001) and DHT (decrease by 90%, p = 0.01), but not in patients with EHT (decrease by 6%, p = 0.6). Head tremor frequencies showed no significant changes in relation to the trick maneuvers. We conclude that a significant reduction of head tremor amplitude during a sensory trick maneuver is a useful quantitative criterion to distinguish TCD and DHT from EHT.

Adrenergic beta-Antagonists↗

Astigmatism correction with a foldable toric intraocular lens in cataract patients.

PURPOSE: To determine the efficacy and rotational stability of a toric posterior chamber silicone intraocular lens (IOL) to correct preoperative astigmatism in cataract patients. SETTING: Department of Ophthalmology, University Hospital of Vienna, Vienna Austria. METHODS: Between 1993 and 1998, foldable toric single-piece plate-haptic silicone IOLs were implanted in 37 eyes (30 patients). The cylindrical IOL power was 2.00 diopters (D) (n = 29), 3.50 D (n = 7), or 4.00 D (n = 1). Phacoemulsification was performed through a scleral or a corneal sutureless self-sealing incision. Outcomes of Snellen visual acuity (without, with spherical, and with best correction), refractive and keratometric astigmatism, and IOL rotation after early postoperative (mean 15.9 days +/- 10.1 [SD]) and long-term (mean 20.3 +/- 16.6 months) follow-ups were evaluated. RESULTS: At last follow-up, 31 eyes (83.8%) had a spherically corrected and 34 (91.9%) a best corrected visual acuity of 0.5 (20/40) or better. Mean preoperative refractive and keratometric astigmatism was 2.68 and 2.70 D, respectively. At the last postoperative follow-up, mean refractive astigmatism was reduced to 0.84 D; keratometric astigmatism was 2.30 D. In 7 eyes (18.9%), the IOL axis was rotated a maximum of 25 degrees. In all 37 eyes, the axis of the toric IOL remained within 30 degrees of rotation. CONCLUSIONS: Early postoperative and long-term follow-ups showed effective and stable correction of astigmatism after implantation of a foldable toric posterior chamber silicone IOL.

Aged↗

A phase I study. UFT/leucovorin combined with paclitaxel for anthracycline-pretreated advanced breast cancer.

Taxanes are the most active drugs in the treatment of metastatic breast and ovarian cancer. Weekly therapy with paclitaxel produces notable activity, with remarkably low toxicity. Moreover, combination therapy with paclitaxel and fluorouracil (5-FU) exhibits high activity in anthracycline-pretreated breast cancer patients: recent studies report response rates of 54% to 69%. UFT plus oral leucovorin constitutes an orally administered compound that provides activity comparable to that of intravenously administered 5-FU plus leucovorin. An open-label phase I study was initiated to determine the maximum tolerated dose and dose-limiting toxicities of the combination of weekly paclitaxel and UFT plus leucovorin administered to patients with anthracycline-resistant metastatic breast cancer.

Administration, Oral↗

Knowledge acquisition, management and representation for the diagnostic support in human inborn errors of metabolism.

The very complex and specific knowledge about inborn errors of metabolism increases rapidly and is spread worldwide. Therefore an Internet platform for the acquisition of statistical knowledge (PATDB) and for the collection of the experience of experts (Metabolic diseases database) has been established. The success of diagnostic support highly depends on the way of knowledge representation. An information retrieval system for physicians will offer first insights about useful user interfaces and handling properties. Furthermore information fusion of biomedical systems to a Biomedical Workbench for the simulation of biochemical reactions is described.

Artificial Intelligence↗

Reduction of Parkinsonian signs in patients with Parkinson's disease by dopaminergic versus anticholinergic single-dose challenges.

We investigated the effect of an anticholinergic (biperiden) and a dopamine agonist (apomorphine) on tremor, rigidity, and akinesia in patients with idiopathic Parkinson's disease. In a standardized, crossover study design 17 patients received single-dose challenges of 5 mg biperiden intravenously and a previously determined dose of apomorphine subcutaneously on 2 consecutive days. Resting (RT), postural (PT), and action tremor (AT) were assessed using spectral analysis of accelerometer data, and Unified Parkinson's Disease Rating Scale (UPDRS) scores for rigidity and akinesia were determined before and after administration of the study drug. Both single-dose challenges significantly reduced the amplitude of RT, PT, and AT, but only apomorphine significantly reduced UPDRS scores for rigidity and akinesia. In only one patient was tremor reduced by the dopamine agonist but not by the anticholinergic. We found that anticholinergic and dopaminergic agents are both effective in reducing tremor in IPD, and there was no evidence for a selective anticholinergic responsiveness of parkinsonian tremor. Akinesia and rigidity, on the other hand, were not improved by biperiden. We therefore conclude that dopaminergic substances are as effective as anticholinergics in patients with parkinsonian tremor and additionally improve other parkinsonian signs.

Adult↗

Electron-probe X-ray Microanalysis of Magnesium and Sodium Ion Content in Vascular Smooth Muscle Cells from Spontaneously Hypertensive and Normotensive Rats.

Whereas in blood cells decreased magnesium concentrations and increased sodium concentrations in essential hypertension have often been described, only sparse data exist on cellular magnesium or sodium content in vascular smooth muscle cells. Therefore, in aortic smooth muscle cells from seven spontaneously hypertensive rats (SHR) of the Münster strain and seven normotensive Wistar-Kyoto rats (WKY), the intracellular magnesium and sodium content were measured by electron-probe X-ray microanalysis. Measurements were performed in aortic cryosections 3 µm thick. The magnesium ion content was 0.93 +/- 0.17 g/kg dry weight in SHR vs 1.14 +/- 0.12 g/kg dry weight in WKY (p < 0.05). Vascular smooth muscle sodium ion content was measured at 6.85 +/- 0.59 g/kg dry weight in WKY and 12.47 +/- 1.62 g/kg dry weight in SHR (p < 0.05). In conclusion, aortic smooth muscle cells from SHR are characterized by a markedly lowered intracellular magnesium ion content and increased sodium ion concentrations compared with normotensive cells. The results may be due to genetically determined disturbances in transmembrane magnesium and sodium ion transport. Cellular magnesium and sodium handling may be disturbed in SHR aortic smooth muscle as it is in hypertensive blood cells.

Journal Article↗

Three-year clinical outcome after penetrating keratoplasty for keratoconus with the guided trephine system.

PURPOSE: To determine the long-term clinical outcome after keratoplasty with the guided trephine system in keratoconus eyes. METHODS: In a prospective study, all consecutive cases of penetrating keratoplasty had trephination performed with the guided trephine system, with which both donor and recipient cornea are trephined from the epithelial side with a same-sized blade. For wound closure, a double running antitorque suture technique with 10-0 nylon was used. Uncorrected and best-corrected Snellen visual acuity, subjective refraction, and astigmatism by keratometry were evaluated after final suture removal, 2 and 3 years postoperatively. RESULTS: In the 31 patients (31 eyes) enrolled, mean best-corrected visual acuity improved from 0.72 +/- 0.16 (20/30) after final suture removal to 0.88 +/- 0.15 (20/25) 3 years postoperatively (P < .001). The mean spherical equivalent increased from -0.86 +/- 2.10 diopters after final suture removal to -2.35 +/- 2.65 diopters 3 years postoperatively (P < .001). Mean keratometric astigmatism decreased from 4.68 +/- 1.76 diopters after final suture removal to 3.57 +/- 1.37 diopters 3 years postoperatively (P = .001). Furthermore, an increase in mean keratometric levels with time (P = .01) was observed and associated with myopic shift (r(s) = -.46, P = .008). CONCLUSION: With the guided trephine system, we attained favorable visual results, with prolonged improvement of visual acuity during the entire follow-up period. Our data show low and decreasing degrees of corneal astigmatism over time. During the follow-up period, a myopic shift was found after final suture removal. Nevertheless, this technique of performing same-sized grafts reduces postoperative residual myopia.

Adult↗

UFT/oral calcium folinate plus weekly paclitaxel for metastatic breast cancer.

Paclitaxel (Taxol) is one of the most active drugs in the treatment of ovarian and breast cancers. Combination therapy with paclitaxel and 5-fluorouracil (5-FU) exhibits high activity in anthracycline-pretreated breast cancer, yielding response rates of 54% to 69% in recent studies. Weekly dosing of paclitaxel produces notable activity, while maintaining relatively low toxicity in heavily pretreated metastatic breast cancer patients. Uracil and tegafur (UFT) plus oral calcium folinate constitute an orally administered compound known as Orzel. This agent provides activity comparable to that of intravenously administered 5-FU plus calcium folinate, with the additional attributes of ease of administration and a more favorable side-effect profile. We initiated a phase I dose-finding trial to determine the maximum tolerated dose and dose-limiting toxicities of the combination of weekly paclitaxel by 1-hour infusion plus UFT/oral calcium folinate administered to patients with anthracycline-resistant metastatic breast cancer.

Administration, Oral↗

Metabolic drug pointing and information processing.

Computer supported drug design is based on the biochemical information for the prediction of alternative bio-chemical pathways. Molecular information on genes, proteins, biochemical reactions, mutations, inborn errors and metabolic diseases are available via internet. Based on this information we developed an information retrieval and processing concept combining knowledge about metabolic diseases and biochemical effects.

Artificial Intelligence↗

Unilateral painful legs and moving toes syndrome with moving fingers--evidence for distinct oscillators.

This case report presents a patient with painful legs and moving toes on the right side followed by the development of involuntary movements in his right hand. The frequencies of the semirhythmic muscle activities in both extremities were different. This finding excludes one central pacemaker for both and supports the notion that separate oscillators in the segmental interneuron pool of different spinal areas may drive the individual movements in this case.

Electromyography↗

Characterization of the pulse signal over the human head by near infrared spectroscopy.

In this study we examine and describe the changes in the hemoglobin oxygenation and the Cytochrome-C-Oxidase redox state that are caused by the pulsatile character of the blood flow in the human head. We used near-infrared spectroscopy (NIRS) in combination with simultaneously recorded ECG and Transcranial Doppler sonography of arteries and veins and show that there is a distinct time lag between heart activity, arterial blood flow, hemoglobin concentration as measured by NIRS and venous blood flow. NIRS has intensively been used to measure functional activation of the brain. When measuring cortical activation by functional stimulation, the pulse signal interferes with the acquired activation signal. We demonstrate that a filter algorithm can remove the pulse artifact and therefore improves the data acquired during visual stimulation.

Adult↗