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T Schneider

Publications and source records attributed to T Schneider.

At least 37 records · Page 2Linked to original sources
PubMed2005

Sub-Hertz optical frequency comparisons between two trapped 171Yb+ ions.

We compare the frequencies of the 6s2S(1/2)(F = 0)-->5d2D(3/2)(F = 2) reference transition in 171Yb+ for two single ions stored in independent traps. The quadrupole moment of the 5d2D(3/2) state is measured to be 9.32(48) x 10(-40) C m2 and from the quadratic Stark shift the relevant scalar and tensor polarizabilities are determined to be alphaS(S(1/2)) - alphaS(D(3/2)) = -6.9(1.4) x 10(-40) J m2/V2 and alphaT(D(3/2)) = -13.6(2.2) x 10(-40) J m2/V2, respectively. In the absence of external perturbations we find a mean frequency difference between the two trapped ions of 0.26(42) Hz, corresponding to a relative difference of 3.8(6.1) x 10(-16). This is comparable to the agreement found in the most accurate comparisons between cesium fountain clocks.

Journal Article↗
PubMed2005

Decreased levels of interleukin-12p40 in the serum of patients with Whipple's disease.

BACKGROUND: An impaired production of interleukin (IL)-12 and T cell interferon-gamma (IFN-gamma) of in vitro stimulated monocytes has been discussed as a pathogenic factor in Whipple's disease (WD). It is unclear whether this defect of cellular immunity is translated to the humoral immune system and to serum correlates. METHODS: We analyzed the serum of 40 patients with Whipple's disease in various degrees of disease activity by sandwich enzyme-linked immunosorbent assay for differences in cytokine and cell adhesion molecule concentrations compared with age- and sex-matched controls. RESULTS: We observed a highly significant reduction of IL-12p40 levels (patients, 0.18+/-0.05 ng/ml (mean+/-SEM); controls, 3.19+/-0.39 ng/ml; p<0.01) in all stages of disease activity, whereas the concentration of IL-12p70 was comparable with controls. Furthermore, we observed a slight decrease in tumour necrosis factor alpha (TNF-alpha) concentrations in the serum of patients (patients, 6.36+/-0.90 pg/ml; controls, 10.5+/-1.23 pg/ml; p<0,05). The levels of other cytokines such as IFN-gamma, IL-2, IL-13 and transforming growth factor beta, as well as soluble cell adhesion molecules lymphocyte function-associated antigen 3 and intercellular adhesion molecule 1, were not significantly different compared with controls. Levels of immunoglobulin G2 (IgG2) measured in the serum of WD patients were below normal in 24 of 29 patients and were even below the 95% confidence interval in 10 patients. CONCLUSION: Our data demonstrate a persistent defect of the cellular immune response with decreased serum concentrations of IL-12p40 and TNF-alpha and decreased IgG2 levels in a large group of WD patients. These data support as in vivo finding the results obtained in previous investigations with stimulated monocytes/lymphocytes. The isolated decrease in IL-12p40 may hint at possible defects in the IL-12/IFN-gamma promoter system.

Biomarkers↗
PubMed2005

Evidence for charged critical behavior in the pyrochlore superconductor RbOs2O6.

We analyze magnetic penetration depth (lambda) data of the recently discovered superconducting pyrochlore oxide RbOs(2)O(6). Our results strongly suggest that in RbOs(2)O(6) charged critical fluctuations dominate the temperature dependence of lambda near T(c). This is in contrast with the mean-field behavior observed in conventional superconductors and the uncharged critical behavior found in nearly optimally doped cuprate superconductors. However, this finding agrees with the theoretical predictions for charged criticality and the charged criticality observed in underdoped YBa(2)Cu(3)O(6.59).

Journal Article↗
PubMed2005

Real-time microbe detection based on director distortions around growing immune complexes in lyotropic chromonic liquid crystals.

We describe director distortions in the nematic liquid crystal (LC) caused by a spherical particle with tangential surface orientation of the director and show that light transmittance through the distorted region is a steep function of the particle's size. The effect allows us to propose a real-time microbial sensor based on a nontoxic lyotropic chromonic LC (LCLC) that detects and amplifies the presence of immune complexes. A cassette is filled with LCLC, antibody, and antigen-bearing particles. Small and isolated particles cause no macroscopic distortions of the LCLC. Upon antibody-antigen binding, the growing immune complexes distort the director and cause detectable optical transmittance between crossed polarizers.

Antigen-Antibody Complex↗
PubMed2005

A hypothesis: autonomic rhythms are reflected in growth lines of teeth in humans and extinct archosaurs.

A major determinant of tooth architecture is the arrangement of lines in dentin and in the enamel following the contour of the surface. Since the original description of these lines in the 19th century, they have been attributed to recurring events during tooth development. They have also attracted the attention of dental scientists and anthropologists; however, to date, studies of these structures have been largely theoretical and microscopic. We show here that the statistical properties of the spacing between the lines are similar in teeth from both ancient and modern humans and from extinct archosaurs, reptiles that lived tens or hundreds of millions of years ago-they also resemble heart rate variability of living humans. We propose that the deposition of these recurring structures is controlled by the autonomic nervous system. This control accounts for their regularity and recurrent nature and implies that the lines are an expression of a biologic rhythm which has been conserved throughout evolution. Details of the rhythms give clues to life styles in ancient civilizations and to the physiology of extinct archosaurs.

Animals↗
PubMed2005

Imported leishmaniasis in Germany 2001-2004: data of the SIMPID surveillance network.

Leishmaniasis is a rare, non-notifiable disease in Germany. Epidemiological and clinical data, therefore, are scarce. Most infections seen in Germany are contracted outside the country. The German surveillance network for imported infectious diseases (Surveillance Importierter Infektionen in Deutschland, or SIPMID) recorded 42 cases of imported leishmaniasis (16 visceral, 23 cutaneous, and 3 mucocutaneous) from January 2001 to June 2004. Although most infections were acquired in European Mediterranean countries, the risk of infection was highest for travelers to Latin America. HIV coinfection was observed significantly more often in patients with visceral leishmaniasis than in patients with cutaneous/mucocutaneous leishmaniasis (31 vs. 4%, p=0.02). The median time to a definitive diagnosis was 85 days in cases of visceral leishmaniasis and 61 days in cases of cutaneous/mucocutaneous leishmaniasis, reflecting the unfamiliarity of German physicians with leishmanial infections. Visceral leishmaniasis was treated most frequently with amphotericin B, whereas cutaneous/mucocutaneous leishmaniasis was treated with a variety of local and systemic therapies. The findings presented here should serve to increase awareness as well as improve clinical management of leishmaniasis in Germany.

Adolescent↗
PubMed2005

[Eva-Reha: a computer software supporting outcome-based quality management in medical rehabilitation].

PURPOSE: Development of a computer software for supporting medical quallity management by documenting progression and results of medical rehabilitation in neurologic, orthopaedic, and geriatric patients. METHODS: The software "Eva-Reha" (Evaluation of Medical Rehabilitation) was generated using C ++ in a client-server structure with Interbase being the underlying relational database management system. The software is network-compatible and runs under Windows NT and Windows 2000. RESULTS: "Eva-Reha", developed by the "Medizinischer Dienst der Krankenversicherung Rheinland-Pfalz (MDK RLP)" supports quality management systems in medical rehabilitation. Since 2003 the MDK RLP provides neurologic and geriatric rehabilitation centres with the software free of charge. With the help of "Eva-Reha" progression and results of medical rehabilitation can be displayed metrically, thus facilitating individual rehabilitation planning and supporting motivation of the rehabilitation team. Therapeutic strategies can be evaluated for different ICD-10-diagnoses or impairment groups. Moreover, "Eva-Reha" provides valuable data for administration and controlling purposes, e. g. age structure, case mix, impairment on admission and medical as well as rehabilitative procedures. The system generates a request for extension in a set form which facilitates communication between rehabilitation centres and sponsors.

Aged↗
PubMed2005

Presynaptic 'Ca2.3-containing' E-type Ca channels share dual roles during neurotransmitter release.

Ca2+ influx into excitable cells is a prerequisite for neurotransmitter release and regulated exocytosis. Within the group of ten cloned voltage-gated Ca2+ channels, the Ca(v)2.3-containing E-type Ca2+ channels are involved in various physiological processes, such as neurotransmitter release and exocytosis together with other voltage-gated Ca2+ channels of the Ca(v)1, Ca(v)2 and Ca(v)3 subfamily. However, E-type Ca2+ channels also exhibit several subunit-specific features, most of which still remain poorly understood. Ca(v)2.3-containing R-type channels (here called 'E-type channels') are also located in presynaptic terminals and interact with some synaptic vesicle proteins, the so-called SNARE proteins, although lacking the classical synprint interaction site. E-type channels trigger exocytosis and are also involved in long-term potentiation. Recently, it was shown that the interaction of Ca(v)2.3 with the EF-hand motif containing protein EFHC1 is involved in the aetiology and pathogenesis of juvenile myoclonic epilepsy.

Amino Acid Sequence↗
PubMed2005

Airborne particle deposition onto the ocular surface.

UNLABELLED: Eye irritation is one of the most frequently reported symptoms in relation to working in office-like environments. So far, no consistent association has been found between concentration of airborne particles and prevalence of eye irritation. External physical factors not hitherto considered could have a large influence on particle deposition velocity onto the ocular surface. This may have obscured the role airborne particles play. Based on previously published semi-empirical models, the paper describes the influence of turbulence, gravitational settling, electrical fields, and thermophoresis on deposition velocity. A probabilistic approach was used to determine percentile ranges in deposition velocity when the magnitude of these parameters varied within typical ranges. The calculations suggest that differences in external factors other than particle size may cause differences in the deposition velocity of one order of magnitude or more. Studies trying to find associations between airborne particle concentration levels and eye irritation should take into consideration the influence of external physical factors on deposition velocity. PRACTICAL IMPLICATIONS: External physical factors other than concentration are likely to have a large influence on the deposition rate of airborne particles onto the ocular surface. Thus, future studies on associations between airborne particle levels and eye symptoms should only be conducted if particle concentration measurements are suitably size resolved. Other relevant external physical factors should also be assessed and included in a multivariate analysis of exposure-response associations.

Air Movements↗
PubMed2005

H19 expression in hepatic metastases from a range of human carcinomas.

AIMS: To investigate the expression of the imprinted oncofetal H19 gene in hepatic metastases derived from a range of human carcinomas and assess its prognostic value with the view of developing a DNA based treatment for such metastases. METHODS: Non-radioactive in situ hybridisation for H19 RNA was performed on paraffin wax embedded sections of liver biopsies or partial hepatectomy specimens, taken from 80 patients with hepatic metastases derived from carcinomas from several medical centres in Israel. The degree of expression was graded qualitatively according to the number of cells expressing H19 and the intensity of staining. The medical files were searched for demographic data and survival times before and after diagnosis of hepatic metastases. RESULTS: H19 expression was found in the hepatic metastases of 64 of 80 patients. High expression (higher staining grades) of H19 in the metastases was found in 43 of 80 patients. However, H19 expression status in the hepatic metastases did not correlate with either the length of time to development of metastasis or overall survival. CONCLUSIONS: H19 is highly expressed in more than half of hepatic metastases derived from a range of carcinomas. Thus, these metastases may be suitable candidates for H19 DNA based treatment. Further studies are needed to determine whether H19 expression has prognostic value in metastatic liver disease using larger numbers of specific subtypes of primary carcinomas.

Adenocarcinoma↗
PubMed2004

Limit on the present temporal variation of the fine structure constant.

The comparison of different atomic transition frequencies over time can be used to determine the present value of the temporal derivative of the fine structure constant alpha in a model-independent way without assumptions on constancy or variability of other parameters, allowing tests of the consequences of unification theories. We have measured an optical transition frequency at 688 THz in 171Yb+ with a cesium atomic clock at 2 times separated by 2.8 yr and find a value for the fractional variation of the frequency ratio f(Yb)/f(Cs) of (-1.2+/-4.4)x10(-15) yr(-1), consistent with zero. Combined with recently published values for the constancy of other transition frequencies this measurement sets an upper limit on the present variability of alpha at the level of 2.0x10(-15) yr(-1) (1sigma), corresponding so far to the most stringent limit from laboratory experiments.

Journal Article↗
PubMed2004

Designing an acupuncture study to meet evidence-based medical criteria: methodological considerations for logistic design and development of treatment interventions arising from the German randomized controlled acupuncture trial on chronic shoulder pain (GRASP).

The results from studies on potential treatment effects of acupuncture are often limited due to serious difficulties in methodology. Randomized controlled trials on acupuncture should test a widely accepted treatment strategy of verum and sham acupuncture. However, in clinical practice various patterns of acupuncture techniques are employed, and up to now no generally accepted guidelines on how to perform a reliable verum or sham treatment have been established. Another limitation is that in most studies the study populations are too small to obtain reliable data and to detect subtle differences between the unspecific needling of sham acupuncture and specific needling of verum acupuncture with sufficient statistical power. Moreover, only a multicenter trial in an outpatient setting would guarantee a naturalistic environment in which acupuncture is used in clinical practice. In the present report we discuss such methodological aspects in detail and summarize some practical considerations for planning an acupuncture trial that fulfills evidence-based medical criteria. The largest German study on the treatment effects of acupuncture in patients with chronic shoulder pain (recruited patients n = 452), might serve as an example for such a well-designed study. Before we could conduct our study, clear definitions and protocols for the verum and sham acupuncture treatments as well as adequate endpoints had to be developed. For this we used a combination of a comprehensive study of the literature and structured interviews with experienced physicians followed by an expert panel. A total of 41 physicians had to be trained to achieve a homogeneously high quality of acupuncture treatment. The latter represents a prerequisite for reproducibility, constituting a critical component of rigorous efficacy trials in scientific acupuncture research.

Acupuncture Therapy↗
PubMed2004

Element distribution in mycorrhizal and nonmycorrhizal roots of the halophyte Aster tripolium determined by proton induced X-ray emission.

The salt aster (Aster tripolium L.) colonized by the arbuscular mycorrhizal fungus Glomus intraradices Sy167 and noncolonized control plants were grown in a greenhouse for nine months with regular fertilization by Hoagland nutrient solution supplemented with 2% NaCl. Mycorrhizal roots showed a high degree of mycorrhizal colonization of 60-70% and formed approximately 25% more dry weight and much less aerenchyma than the nonmycorrhizal controls. Cryosectioning essentially preserved the root cell structures and apparently did not cause significant ion movements within the roots during cuttings. The experimental conditions, however, did not allow to discriminate between fungal and plant structures within the roots. Quantification of proton-induced X-ray emission (PIXE) data revealed that in control roots, Na(+) was mainly concentrated in the outer epidermal and exodermal cells, whereas the Cl(-) concentration was about the same in all cells of the roots. Cross sections of roots colonized by the mycorrhizal fungus did not show this Na(+) gradient in the concentration from outside to inside but contained a much higher percentage of NaCl among the elements determined than the controls. PIXE images are also presented for the four other elements K, P, S, and Ca. Both in colonized and control roots, the concentration of potassium was high, probably for maintaining homoeostasis under salt stress. This is seemingly the first attempt to localize both Na(+) and Cl(-) in a plant tissue by a biophysical method and also demonstrates the usefulness of PIXE analysis for such kind of investigation.

Aster Plant↗
PubMed2004

Microbial dustiness and particle release of different biofuels.

Exposure to organic dust originating from biofuels can cause adverse health effects. In the present study we have assessed the dustiness in terms of microbial components and particles of various biofuels by using a rotating drum as a dust generator. Microbial components from straw, wood chips, wood pellets and wood briquettes were quantified by several methods. Excellent correlations (r >/= 0.85, P < 0.0001) were found: between lipopolysaccharide (LPS) (as determined by 3-hydroxy fatty acid analysis) and endotoxin (as determined by a Limulus test), cultivable bacteria, total number of bacteria and muramic acid; between endotoxin and cultivable bacteria, total number of bacteria and muramic acid; between total number of bacteria and muramic acid; between cultivable fungi and total number of fungi. Straw was dustier than the other biofuels in terms of actinomycetes, bacteria, muramic acid, endotoxin, LPS, particle mass and number of particles. One of the wood chips studied and the straws had comparatively high dustiness in terms of fungi, while both wood pellets and wood briquettes had comparatively low dustiness in terms of all microbial components. An initially high particle generation rate of straw and wood chips decreased over time whereas the particle generation rate of wood briquettes and wood pellets increased during a 5 min rotation period. Particles of non-microbial origin may be the determining factor for the health risk in handling briquettes and pellets. Straw dust contained significantly more microorganisms per particle than did wood chip dust, probably because bacteria were most abundant in straw dust. The concentrations of endotoxin and fungi were high in wood and straw dust; dust from one of the straws contained 3610 EU/mg and dust from one of the chips contained 7.3 x 10(6) fungal spores/mg. An exposure to 3 mg of straw or wood chips dust/m(3) (the Swedish and Danish OEL of unspecific inhalable dust) could cause exposures to endotoxin and fungi higher than levels were health symptoms are seen to develop. The very different levels of dustiness in terms of particles and microbial components of different biofuels shows that dustiness is an important health-relevant factor to consider when choosing among biofuels and when designing worksites for handling of biofuels.

Air Microbiology↗
PubMed2004

Subatomic and atomic crystallographic studies of aldose reductase: implications for inhibitor binding.

The determination of several of aldose reductase-inhibitor complexes at subatomic resolution has revealed new structural details, including the specific interatomic contacts involved in inhibitor binding. In this article, we review the structures of the complexes of ALR2 with IDD 594 (resolution: 0.66 angstrom, IC50 (concentration of the inhibitor that produced half-maximal effect): 30 nM, space group: P2(1)), IDD 393 (resolution: 0.90 angstrom, IC50: 6 nM, space group: P1), fidarestat (resolution: 0.92 angstrom, IC50: 9 nM, space group: P2(1)) and minalrestat (resolution: 1.10 angstrom, IC50: 73 nM, space group: P1). The structures are compared and found to be highly reproductible within the same space group (root mean square (RMS) deviations: 0.15 approximately 0.3 angstrom). The mode of binding of the carboxylate inhibitors IDD 594 and IDD 393 is analysed. The binding of the carboxylate head can be accurately determined by the subatomic resolution structures, since both the protonation states and the positions of the atoms are very precisely known. The differences appear in the binding in the specificity pocket. The high-resolution structures explain the differences in IC50, which are confirmed both experimentally by mass spectrometry measures of VC50 and theoretically by free energy perturbation calculations. The binding of the cyclic imide inhibitors fidarestat and minalrestat is also described, focusing on the observation of a Cl(-) ion which binds simultaneously with fidarestat. The presence of this anion, binding also to the active site residue His110, leads to a mechanism in which the inhibitor can bind in a neutral state and then become charged inside the active site pocket. This mechanism can explain the excellent in vivo properties of cyclic imide inhibitors. In summary, the complete and detailed information supplied by the subatomic resolution structures can explain the differences in binding energy of the different inhibitors.

Aldehyde Reductase↗
PubMed2004

[Diabetes mellitus as a complication of treatment with atypical neuroleptics. Possible pathomechanisms and treatment recommendations].

An increased risk for occurrence of diabetic metabolic states has been reported for treatment with atypical antipsychotics. Initial studies suggest that atypical antipsychotics as a heterogeneous group of substances are not equally concerned. An increased risk for development of diabetes mellitus can be assumed for clozapine and olanzapine, while other atypical and conventional antipsychotics seem to carry only a slightly elevated risk. It remains as yet unresolved whether there is a causal connection or whether other not yet identified factors are involved. However, atypical antipsychotics intervene in various ways in glucose and fatty acid metabolism due to their broad receptor profile. We suggest that some atypical antipsychotics disturb regulatory loops of fat metabolism in fatty tissue and muscle,which may result in insulin resistance and finally diabetes. Changes in leptin release and development of leptin resistance possibly play an important role. These new results should be considered when planning therapy, although a final risk analysis is not yet possible.

Antidepressive Agents, Second-Generation↗
PubMed2004

[Stinging nettle root extract (Bazoton-uno) in long term treatment of benign prostatic syndrome (BPS). Results of a randomized, double-blind, placebo controlled multicenter study after 12 months].

Phytotherapy of BPS has a long tradition in Germany; nevertheless, data referring to single phytotherapeutic agents are rare. We therefore performed a randomized, double-blind, placebo-controlled multicenter study for 1 year with Bazoton uno (459 mg dry extract of stinging nettle roots) with 246 patients. The IPSS decreased on average from 18.7+/-0.3 to 13.0+/-0.5 with a statistically significant difference compared to placebo (18.5+/-0.3 to 13.8+/-0.5; p=0.0233). The median Q(max) increased by 3.0+/-0.4 ml/s in comparison to 2.9+/-0.4 ml/s (placebo), thus not statistically significantly different, as well as the median volume of residual urine, which changed from 35.5+/-3.4 ml before therapy to 20.0+/-2.8 ml and from 40.0+/-4.0 ml to 21.0+/-2.9 ml under placebo application. The number of adverse events (29/38) as well as urinary infections etc. (3/10 events) was smaller under Bazoton uno therapy compared to placebo. Treatment with Bazoton uno can therefore be considered a safe therapeutic option for BPS, especially for reducing irritative symptoms and BPS-associated complications due to the postulated antiphlogistic and antiproliferative effects of the stinging nettle extract. A strong increase of Q(max) or reduction of residual urine are not to be expected.

Aged↗