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T Schmidt

Publications and source records attributed to T Schmidt.

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

Professionalism in emergency medicine. SAEM Ethics Committee. Society for Academic Emergency Medicine.

The Society for Academic Emergency Medicine (SAEM), with the support and participation of the American Board of Emergency Medicine (ABEM), the Council of Residency Directors (CORD), the American College of Emergency Physicians (ACEP), the Emergency Medicine Residents Association (EMRA), the American Academy of Emergency Medicine (AAEM), and the Association of Academic Chairs of Emergency Medicine (AACEM), initiated a project entitled Professionalism in Emergency Medicine. Its concepts were developed by the SAEM Ethics Committee, and are intended to describe proper behaviors and attitudes of the successful practitioner of emergency medicine. The behaviors described are not primarily scientific or technical, since those are defined by the core curriculum for residency training and are tested through certification examinations. This document identifies attitudes and behaviors that enhance trust by placing the patient's interest above other interests. This concept serves as the operative definition of professionalism. The purpose of this article is to clarify the professional attitudes and knowledge that are important to the emergency physician (EP). While no physician is likely to meet idealized standards, all EPs must meet basic standards while striving for the ideal. Awareness of these standards must begin early in the socialization process of emergency medical professionals. The standards must be integrated into residency training as well as the clinical practice of all EPs.

Attitude↗
PubMed1998

An isoform of ataxin-3 accumulates in the nucleus of neuronal cells in affected brain regions of SCA3 patients.

Autosomal dominant spinocerebellar ataxias (SCA) form a group of clinically and genetically heterogeneous neurodegenerative disorders. The defect responsible for SCA3/Machado-Joseph disease (MJD) has been identified as an unstable and expanded (CAG)n trinucleotide repeat in the coding region of a novel gene of unknown function. The MJD1 gene product, ataxin-3, exists in several isoforms. We generated polyclonal antisera against an alternate carboxy terminus of ataxin-3. This isoform, ataxin-3c, is expressed as a protein of approximately 42 kDa in normal individuals but is significantly enlarged in affected patients confirming that the CAG repeat is part of the ataxin-3c isoform and is translated into a polyglutamine stretch, a feature common to all known CAG repeat disorders. Ataxin-3 like immunoreactivity was observed in all human brain regions and peripheral organs studied. In neuronal cells of control individuals, ataxin-3c was expressed cytoplasmatically and had a somatodendritic and axonal distribution. In SCA3 patients, however, C-terminal ataxin-3c antibodies as well as anti-ataxin-3 monoclonal antibodies (1 H9) and anti-ubiquitin antibodies detected intranuclear inclusions (NIs) in neuronal cells of affected brain regions. A monoclonal antibody, 2B6, directed against an internal part of the protein, barely detected these NIs implying proteolytic cleavage of ataxin-3 prior to its transport into the nucleus. These findings provide evidence that the alternate isoform of ataxin-3 is involved in the pathogenesis of SCA3/MJD. Intranuclear protein aggregates appear as a common feature of neurodegenerative polyglutamine disorders.

Amino Acid Sequence↗
PubMed1998

Basal metabolism does not account for high O2 consumption in stunned myocardium.

Myocardial O2 consumption (MVo2) in stunned myocardium is relatively high compared with the reduced ventricular function. The mechanism of this "oxygen paradox" could occur at different levels: basal metabolism, excitation-contraction coupling, and energy production. In one previously reported series on 12 isolated, blood-perfused rabbit hearts, left ventricular systolic and diastolic function in stunned myocardium were significantly decreased compared with control, whereas total MVo2 was not. The MVo2 for the unloaded contraction was overproportionately high for the decreased function in stunned myocardium, and contractile efficiency was clearly deteriorated. To assess whether the basal metabolism specifically is elevated in stunned myocardium, a second series (n = 14) with a similar protocol was performed in this study. Basal MVo2 after KCl arrest (0.5 +/- 0.3 ml.min-1.100 g-1) was significantly lower than that measured after KCl arrest (1.2 +/- 0.5 ml.min-1.100 g-1) in an additional series on nonischemic hearts (n = 8). Our conclusion is that basal MVo2 in stunned myocardium is not elevated. Thus this O2-consuming portion of total MVo2 is not responsible for the inefficiency in stunned myocardium. Instead, a "metabolic stunning" occurs at the level of both excitation-contraction coupling and force development by the contractile apparatus.

Animals↗
PubMed1998

Photoallergic contact dermatitis due to combined UVB (4-methylbenzylidene camphor/octyl methoxycinnamate) and UVA (benzophenone-3/butyl methoxydibenzoylmethane) absorber sensitization.

In a 71-year-old male Caucasian patient with persistent eczema on light-exposed skin, photocontact allergy was demonstrated to the UV filter substances 4-methylbenzylidene camphor (UVB), octyl methoxycinnamate (UVB), benzophenone-3 (UVA) and butyl methoxydibenzoylmethane (UVA) present in sunscreen products used by the patient over several years. A significantly reduced UVB sensitivity of 25 mJ/cm2 in this patient (normal minimal erythema dose in our laboratory = 70-130 mJ/cm2) was considered an early indication of a persistent light reaction. Topical anti-inflammatory treatment over 2 weeks together with consequent application of a sunscreen containing Mexoryl SX/titanium dioxide led to complete remission. Taking into account the widespread use of the above UV filter substances not only in sun protection products, but also in cosmetics such as antiaging lotions and day care products, the possible risk of allergy to these chemicals has to be taken seriously. The substitution of known photocontact sensitizers in UV filters by photostable compounds and detailed product information are the basis of preventive strategies.

Aged↗
PubMed1998

[Degree of oxidation and crystallinity of vacuum packaged gamma sterilized ultra-high molecular weight polyethylene].

The oxidation index of a new vacuum-packed and gamma sterilized UHMWPE was determined using infrared spectroscopy, and the crystallinity using differential scanning calorimetry. The CO numbers ranged from 0.053 to 0.154 (mean: 0.098). Crystallinity values ranged between 63.1% and 63.8% (mean: 63.4%). The low oxidation indices reflected the positive effect of vacuum gamma sterilization. What effect the small increase in crystallinity will have in the long run needs to be investigated in further studies.

Calorimetry, Differential Scanning↗
PubMed1998

[Principles in the assessment of radiation exposure in interventional measures].

Interventional procedures undoubtedly involve a high radiation exposure, for the patient. For some interventional procedures the frequencies of procedures, radiation exposures and considerations to the radiation risk are shown and discussed. Radiation risk is calculated with the currently common assumptions but always in consideration of the age and expectation of life of the patient. The risk coefficient used for the age-distribution of the common population is 5% per Sv, but for the risk coefficient for, e.g., the group of PTA patients 1.0% per Sv can be derived. That's why the risk of cancer increases in this patient group by 5/100,000. This risk must be balanced with the immediate benefit and the risk of alternative procedures.

Adolescent↗
PubMed1998

[Group housing for two to eight week old fattening calves].

The effect of three different feeding techniques (electronic automated feeder, teat bucket and bucket with floating teat) on oral activities, skin condition, health and performance of 144 German Holstein group housed veal calves was investigated. About 21% of the observed time over 24 hours was spent on oral activities and only about 1% with the particularly health-relevant activities at prepuce, navel or scrotum. As a consequence of sucking activities at pen mates in most cases reddening of the skin and, with low incidence (about 7%), additional loss of hair could be found. Altogether about 74% of the calves were affected with the highest incidence in the electronic automated feeder groups. Calves of these groups had, moreover, higher disease incidences and a lower weight gain and feed conversion rate than those fed by teat bucket or by bucket with floating teat. Altogether results show that in terms of behaviour and health it is possible to keep calves at the age of two weeks in groups, even in conventional veal calf production, when satisfactory management is applied. The electronic automated feeder still needs further technical development for use with veal calves.

Animal Feed↗
PubMed1998

[Radiation protection in the European Community and in Germany].

During the last few months, administrations of both the European Community and Germany have brought up several recommendations and changes concerning radiation protection. The European changes must become national law by 13th May, 2000. The changes focus on better protection of children and pregnant women. When performing X-ray examinations, strict indications will have to be observed.

Child↗
PubMed1998

Analysis of blood vessel maturation processes during cyclic ovarian angiogenesis.

Cyclic angiogenic processes in the ovarian corpus luteum (CL) of monovulatory species are characterized by distinct phases of blood vessel growth, vessel maturation, and vessel regression. To characterize molecular and cellular systems that may play a role in regulating blood vessel maturation, we have (a) analyzed the spatiotemporal expression of vascular endothelial growth factor (VEGF) and its receptors VEGF-R1 (Flt-1) and VEGF-R2 (Flk-1) throughout the ovarian cycle, (b) examined the recruitment of pericytes during vessel maturation, and (c) quantitatively measured the ratio of angiopoietin-2 (Ang-2) to angiopoietin-1 (Ang-1) throughout the ovarian cycle. The data indicate that the VEGF/VEGF-receptor system is expressed not only during ovarian angiogenesis, but also with similar intensity in the nonangiogenic midstage CL. In fact, VEGF is expressed through most of the ovarian cycle, only being down-regulated during luteolysis, which leads to regression of the CL neovasculature. Pericytes are recruited soon after the induction of CL angiogenesis following the front of invading endothelial cells. Based on a double-staining immunohistochemistry technique, we developed a microvessel maturation index (MMI) that reflects the percentage of the capillary neovasculature that is associated with pericytes. The MMI in the angiogenic corpus rubrum is approximately 0.60. This value is not significantly higher in the nonangiogenic midstage CL but increases to close to 0.90 during CL regression. Lastly, an RT-PCR analysis of Ang-1 and Ang-2 expression revealed that both molecules are expressed throughout the ovarian cycle. The quantitative Ang-2/Ang-1 ratio does, however, change from 1.34 in the angiogenic CL and 1.07 in the midstage CL to 7.59 during CL regression, reflecting the strong overexpression of Ang-2 over Ang-1 during blood vessel regression. Taken together, the data support a model of a transiently maturated vasculature in the midstage CL, which is characterized by VEGF and pericyte contact-mediated endothelial cell survival and an induction of blood vessel regression during luteolysis that is characterized by the down-regulation of VEGF and the up-regulation of Ang-2.

Angiopoietin-1↗
PubMed1998

Gianotti-Crosti syndrome: clinical, serologic, and therapeutic data from nine children.

Gianotti-Crosti syndrome (GCS), a self-limiting papulovesicular acrodermatitis often associated with underlying viral infection, is mainly described in children. Nine children with GCS were evaluated with dermatologic examination and serologic tests for viral infections. Therapy was modified according to the subjective symptoms of patients, which included characteristic acrolocated papulovesicles, generalized skin eruption, and mild to severe pruritus. Results of serologic investigations revealed Epstein-Barr virus, Coxsackie A virus, parvovirus B19, and parainfluenza virus 1/2. In three children no underlying viral infection was found. Therapeutic interventions included topical clioquinol lotion 1 percent, topical application of corticosteroids, systemic antihistaminic therapy, and systemic methylprednisolone. Skin lesions resolved after 2 to 4 weeks in treated as well as in nontreated children. Although GCS in children often lacks close association with a causative viral infection, such severe infections as hepatitis B and human immunodeficiency virus must be considered. Whole-body involvement seems to correlate with severe pruritus and additional general symptoms requiring more intensive therapy.

Acrodermatitis↗
PubMed1997

Malignant transformation by cyclin E and Ha-Ras correlates with lower sensitivity towards induction of cell death but requires functional Myc and CDK4.

We demonstrate in this paper that the G1 phase specific cell cycle regulator cyclin E is able to provoke focus formation when cotransfected with activated Ha-ras into primary rat embryo fibroblasts (REFs). Cyclin E/Ha-ras transformed cells are highly tumorigenic in synergeneic rats, are able to form colonies in soft agar and show protection towards apoptosis upon serum starvation or DNA damage compared to cells transformed by the combination of Myc, cyclin D1 or SV40 large T-antigen and Ha-ras. Lines that were established after cyclin E/Ha-ras or cyclin D1/Ha-ras transformation contain a large percentage of polyploid cells. This was not observed in cells transformed with other oncoproteins and Ha-ras pointing to an involvement of D- and E type cyclins in genomic instability. The cyclin dependent kinase inhibitors p21 and p27 but also p16 completely abrogate focus formation by cyclin E and Ha-ras suggesting that the oncogenic activity of cyclin E still requires functional G1 specific cyclin/CDK complexes. Moreover, inhibition of Myc function also blocks the oncogenic activity of cyclin E indicating a requirement of Myc for cyclin E function. The findings presented here demonstrate that cyclin E can act as an oncoprotein with a potential involvement in genomic instability and the prevention of cell death. Our data also present more evidence for a strict functional interdependency between G1 cyclin/CDK complexes and c-Myc.

Animals↗
PubMed1997

GA-binding protein-dependent transcription initiator elements. Effect of helical spacing between polyomavirus enhancer a factor 3(PEA3)/Ets-binding sites on initiator activity.

Many eukaryotic RNA polymerase II promoters contain initiator elements which direct accurate transcription in a TATA-independent manner. The PEA3/Ets-binding site (PEA3/EBS) is a common enhancer element in eukaryotic genes and is also found near the transcriptional start sites of many TATA-less promoters. We demonstrate that two PEA3/EBSs driving expression of the luciferase reporter gene, function as a minimal transcriptional initiator element. Maximal levels of transcription was achieved when two PEA3/EBSs, in either orientation, were located on the same face of the DNA helix, and the sites could be separated by up to three helical turns. In vitro transcription start sites directed by PEA3/EBS elements were clustered on either side of the upstream PEA3/EBS and were abolished by immunodepletion of GA-binding protein (GABP) from FM3A cell nuclear extracts. In vivo, co-transfection of GABPalpha and GABPbeta expression vectors enhanced reporter gene expression driven from PEA3/EBS initiator elements. Like other initiator elements, the PEA3/EBS elements were activated synergistically by upstream Sp1-binding sites. Thus, our results establish GABP as both a transcriptional activator factor and as an initiator factor.

3T3 Cells↗
PubMed1997

A family of differentially amplified repetitive DNA sequences in the genus Beta reveals genetic variation in Beta vulgaris subspecies and cultivars.

Members of a highly abundant restriction satellite family have been isolated from the wild beet species Beta nana. The satellite DNA sequence is characterized by a conserved RsaI restriction site and is present in three of four sections of the genus Beta, namely Nanae, Corollinae, and Beta. It was not detected in species of the evolutionary old section Procumbentes, suggesting its amplification after separation of this section. Sequences of eight monomers were aligned revealing a size variation from 209 to 233 bp and an AT content ranging from 56.5% to 60.5%. The similarity between monomers in B. nana varied from 77.7% to 92.2%. Diverged subfamilies were identified by sequence analysis and Southern hybridization. A comparative study of this repetitive DNA element by fluorescent in situ hybridization and Southern analyses in three representative species was performed showing a variable genomic organization and heterogeneous localizations along metaphase chromosomes both within and between species. In B. nana the copy number of this satellite, with some 30,000 per haploid genome, is more than tenfold higher than in Beta lomatogona and up to 200 times higher than in Beta vulgaris, indicating different levels of sequence amplification during evolution in the genus Beta. In sugar beet (B. vulgaris), the large-scale organization of this tandem repeat was examined by pulsed-field gel electrophoresis. Southern hybridization to genomic DNA digested with DraI demonstrated that satellite arrays are located in AT-rich regions and the tandem repeat is a useful probe for the detection of genetic variation in closely related B. vulgaris cultivars, accessions, and subspecies.

DNA, Plant↗
PubMed1997

[Fornix reconstruction in ocular pemphigoid with Goretex surgical membrane].

UNLABELLED: After separation of symblepharons in ocular pemphigoid, transplantation of nasal or bucal mucosa is recommended to prevent recurrent lid fusion; however, it is not always successful. BACKGROUND: An 86-year-old patient was referred to our eye clinic because of trichiasis in ocular pemphigoid. In the right eye, the only functional eye, fusion of the lower lid and the globe was present. There was severe trichiasis with multiple lesions of the cornea and beginning neovascularization. The left eye showed complete fusion of the lid fissure and neovascularization of the cornea. To prevent the right eye from suffering the fate of the left, we tried to find a simple surgical method that could easily be performed on the multimorbid patient. METHOD: Under parabulbar anesthesia we separated the lower lid from the globe until free passive motility of the lower lid was achieved. A cut-to-size piece of Gore-Tex surgical membrane was prepared and fixated with resorbable u-sutures on the inner lid. The membrane was left in place for 4 weeks until suture lysis. A silicone tube, which was transitorily fixed to the outer lower lid, had an additional ectropionizing effect. Three months later, lower-lid ectropion surgery was performed, combined with tarsectomy to obtain a long-term effect. RESULT: Six months later the lower-lid fornix had stabilized, and the lid and globe had good motility. The corneal lesions had healed. CONCLUSION: The use of 0.1 mm membrane prevents penetration of cell because of the microstructure. Similar to the "bare sclera" technique, which is used in selected cases in strabismus or pterygium surgery, the inner lid and sclera were epithelialized separately from the remaining conjunctiva. The surgical membrane prevented recurrence of the symblepharon. We think the presented technique is an easy, quick method of preventing recurrence of lid fusion after separation of symblepharons.

Aged↗
PubMed1997

[Melanoma-associated retinopathy with night blindness. Case report].

BACKGROUND: Night blindness is usually symptomatic of retinal dysfunction. However, apart from congenital forms of night blindness such as congenital stationary night blindness (CSNB) and pigmentary retinopathy without clumping of pigment, the acquired forms of night blindness present a particular diagnostic challenge to the ophthalmologist. CASE REPORT: A 51-year-old patient with formerly healthy eyes presented with malignant skin melanoma and sudden night blindness. Along with reduced acuity, concentric visual field limitation, and a marked decrease in sensitivity of the retinal rods and cones in adaptometrical tests, significantly reduced b waves and intact a waves were registered in the flash-ERG of both eyes with otherwise inconspicuous morphologic findings. Furthermore, serum levels of antibodies (IgG) against retinal bipolar cells were found to be increased. CONCLUSION: Results indicate the presence of melanoma-associated retinopathy (MAR), which-like carcinoma-associated retinopathy (CAR)-ranks among the tumor-associated diseases of the retina. CAR, MAR, and CSNB can be differentiated immunohistochemically by serum autoantibody determination and electrophysiologically by flash-ERG. As opposed to CAR, the immune response in the case of MAR is not to antigens of photoreceptors and ganglion cells, but to retinal so-called ON-depolarizing bipolar cells mainly connected in series to the rods. In addition, a waves are intact and b waves extinct, resembling the situation of CSNB.

Autoantibodies↗
PubMed1997

Single-molecule microscopy on model membranes reveals anomalous diffusion.

The lateral mobility of lipids in phospholipid membranes has attracted numerous experimental and theoretical studies, inspired by the model of Singer and Nicholson (1972. Science, 175:720-731) and the theoretical description by Saffman and Delbrück (1975. Proc. Natl. Acad. Sci. USA. 72:3111-3113). Fluorescence recovery after photobleaching (FRAP) is used as the standard experimental technique for the study of lateral mobility, yielding an ensemble-averaged diffusion constant. Single-particle tracking (SPT) and the recently developed single-molecule imaging techniques now give access to data on individual displacements of molecules, which can be used for characterization of the mobility in a membrane. Here we present a new type of analysis for tracking data by making use of the probability distribution of square displacements. The potential of this new type of analysis is shown for single-molecule imaging, which was employed to follow the motion of individual fluorescence-labeled lipids in two systems: a fluid-supported phospholipid membrane and a solid polymerstabilized phospholipid monolayer. In the fluid membrane, a high-mobility component characterized by a diffusion constant of 4.4 microns2/s and a low-mobility component characterized by a diffusion constant of 0.07 micron2/s were identified. It is proposed that the latter characterizes the so-called immobile fraction often found in FRAP experiments. In the polymer-stabilized system, diffusion restricted to corrals of 140 nm was directly visualized. Both examples show the potentials of such detailed analysis in combination with single-molecule techniques: with minimal interference with the native structure, inhomogeneities of membrane mobility can be resolved with a spatial resolution of 100 nm, well below the diffraction limit.

Diffusion↗
PubMed1997

Comparative analysis of the chromosomal and genomic organization of Ty1-copia-like retrotransposons in pteridophytes, gymnosperms and angiosperms.

We have investigated the physical distribution of the reverse transcriptase genes of Ty1-copia-like retrotransposable elements from 12 plant species belonging to different subdivisions by hybridization in situ on chromosome preparations. Ty1-copia-like elements showed different and non-random hybridization patterns. A dispersed distribution throughout most of the chromosomes with reduced hybridization at some regions or with some weak clustering at other regions was found in Allium cepa, Beta vulgaris, Brassica campestris, Brassica oleracea, Pennisetum glaucum, Pinus elliottii, Selaginella apoda, Vicia faba and Vicia narbonensis. Reduced hybridization occurred mainly at centromeric regions, nucleolus-organizing regions and regions known to be mainly composed of tandemly repeated sequences. In the fern Pteris cretica the retroelements showed a dispersed genomic organization with clustering at some chromosomal regions and whole chromosomes showing little signal. In Arabidopsis thaliana and Cicer arietinum Ty1-copia-like elements were found in clusters at the paracentromeric heterochromatin, a novel organization for a repetitive element in A. thaliana. New retroelement families were isolated from A. thaliana and from Beta vulgaris. Alignment of the deduced peptide sequences with Ty1-copia-like elements from other plants showed considerable divergence which was used to calculate their relationships, indicating the value of reverse transcriptase gene analysis in phylogenetic and biodiversity studies.

Amino Acid Sequence↗