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Biomedical subjects

H Schulz

Publications and source records attributed to H Schulz.

At least 55 records · Page 3Linked to original sources
PubMed2002

[Treatment recommendations in psychosomatic rehabilitation -- empirical analyses based on the pension insurers' standardized discharge report].

BACKGROUND: The recommendations for aftercare listed in discharge reports represent a core component of communication between inpatient psychosomatic rehabilitation and ambulatory follow-up care. The standardized discharge report used by the pension insurance institutes makes use of a generic category system for systematization and simplification of recommendations for aftercare. Neither the practice of making recommendations for aftercare as observed by therapists and physicians responsible for treatment in the inpatient setting nor the appropriateness and differentiation of the category system has previously been systematically examined. A randomized sample of discharge reports was analyzed for this purpose. METHODS: A sample of 500 discharge reports from an inpatient-oriented psychosomatic rehabilitation setting were analyzed regarding the categories of recommended aftercare measures and their relationship with socio-demographic variables, clinical diagnosis and sociomedical variables. RESULTS: Outpatient psychotherapy represents the most frequently recommended aftercare treatment, being suggested in nearly 70% of the patients. Further substantial percentages were found in recommendations for areas including occupational rehabilitation, somatic-medical recommendations, and recommendations for health behaviour and self-help groups. In approximately one quarter of the patients, recommendations for aftercare were given that were coded under the category of "other suggestions". In younger and socio-medically burdened patients, recommendations for the fields of occupational rehabilitation and psychotherapy were more frequently given. In patients with a somatic illness or a somatoform disorder as the primary diagnosis, recommendations within the field of outpatient psychotherapy were found less frequently, while recommendations in the somatic-medical area were more commonly found. DISCUSSION: The results give some support for the clinical validity of the form of recommendations given for aftercare measures in an inpatient psychosomatic rehabilitation setting. At the same time, the analyses indicate excessive as well as insufficient differentiation in the generic category system for follow-up treatment recommendations, which could lead to a loss of valuable information at the interface between inpatient and outpatient treatments.

Adult↗
PubMed2002

Current strategies of antibody-based treatment in Hodgkin's disease.

Many new approaches involving antibody-based agents have given promising results in experimental Hodgkin's disease (HD) models. Clinical trials with monoclonal antibodies, immunotoxins, bispecific constructs and radioimmunoconjugates have demonstrated some clinical efficacy in patients with advanced refractory HD. Although it seems unlikely that resistant patients with larger tumor masses will be cured by either of these approaches, it might be feasible to treat bulky disease by conventional therapy and then administer biological agents to kill residual Hodgkin and Reed-Sternberg cells. Future phase III trials will have to prove a possible superior effect of this combined immunochemotherapy. Currently, the evaluation of the most promising approaches continues.

Antibodies, Monoclonal↗
PubMed2002

Diurnal radon variations in the upper soil layers and at the soil-air interface related to meteorological parameters.

Measurements of the radon concentration in a column (1 m2 x 2 m) consisting of a homogeneous mixture of dry sand and uranium tailings have been performed to obtain information on the radon transport under well defined conditions. The dependence of the radon concentration has been exclusively studied on the soil/air temperature gradient and on the wind speed. The soil moisture content has been kept constant. Significant diurnal variations of the radon concentration were detected in the uppermost soil layer and at the soil/air interface. Such a behavior was not found in 30 cm and deeper soil layers. It is argued that the diurnal radon variation in the uppermost soil layer is mainly associated with the diurnal inversion of the soil/air temperature gradient giving rise to a convective soil gas migration additional to the common upward diffusion processes, whereas the diurnal variation of the radon concentration at the soil/air interface is caused by the interplay of the temperature gradient and the wind speed. No impact of atmospheric pressure variations on the radon migration has been observed.

Air↗
PubMed2001

Direct chiral assay of tramadol and detection of the phase II metabolite O-demethyl tramadol glucuronide in human urine using capillary electrophoresis with laser-induced native fluorescence detection.

A chiral separation using carboxymethyl-beta-cyclodextrin and methyl-beta-cyclodextrin for the direct assay of tramadol in human urine by capillary electrophoresis (CE) with laser-induced native fluorescence detection was developed. Furthermore, the phase II metabolite O-demethyl tramadol glucuronide was determined from the urine samples and the ratio of the diasteromers was determined. The chiral method was validated. Correlation coefficients were higher than 0.999. Within day variation showed accuracy in the range 96.1-105.8% with a RSD less than 6.00%. Day to day variation present an accuracy ranging from 100.2 to 103.5% with a RSD less than 5.4%. After oral administration of 150 mg tramadol hydrochloride to a healthy volunteer, the urinary excretion was monitored during 24 h. About 11.4% of the dose was excreted as 1S,2S-tramadol, 16.4% as 1R,2R-tramadol and 23.7% as O-demethyl tramadol glucuronide. The amount of 1S,2S O-demethyl tramadol glucuronide was more than three fold higher as IR,2R-O-demethyl tramadol glucuronide. The enantiomeric ratio of tramadol and the diastereomeric ratio of O-demethyl tramadol glucuronide was deviated from 1.0 showing that a stereoselective metabolism of tramadol occurs.

Analgesics, Opioid↗
PubMed2001

Simultaneous quantification of etoposide and etoposide phosphate in human plasma by capillary electrophoresis using laser-induced native fluorescence detection.

A method using capillary electrophoresis with UV laser-induced native fluorescence detection was developed as a sensitive and selective assay for the simultaneous determination of etoposide and etoposide phosphate in human plasma. Laser-induced native fluorescence detection with a frequency-doubled argon ion laser at an excitation wavelength of 257 nm was used for the simultaneous assay of etoposide and etoposide phosphate in plasma to improve the sensitivity compared to that obtained with UV absorption. The detection system consists of an imaging spectrograph and an intensified CCD camera which views an illuminated 1.5-mm section of the capillary. This setup is able to record the whole emission spectra of the analytes to achieve additional wavelength-resolved electropherograms. In the concentration range of 200 microg/L-50 mg/L in plasma for etoposide and 100 microg/L-20 mg/L for etoposide phosphate, coefficients of correlation were better than 0.998. Within-day variation determined with three different concentrations showed accuracies ranging from 91.0 to 109.3% for etoposide and from 91.2 to 109.9% for etoposide phosphate (n = 6) with a precision of about 8%. Day-to-day variation presented accuracies ranging from 91.8 to 107.9% for etoposide and from 94.4 to 109.3% for etoposide phosphate with a relative standard deviation less than 6% (n = 5). To our knowledge, this is the first method for the simultaneous quantification of etoposide and etoposide phosphate in plasma samples.

Antineoplastic Agents↗
PubMed2001

Molecular cloning, modeling, and localization of rat type 10 17beta-hydroxysteroid dehydrogenase.

Rat and mouse complementary DNAs of type 10 17beta-hydroxysteroid dehydrogenase were cloned and sequenced. The mouse cDNA clone's sequence corrected the previously published nucleotide and amino acid sequence of mouse endoplasmic reticulum-associated beta-amyloid-binding protein. A subunit of the rat enzyme consists of 261 amino acid residues with a calculated molecular mass of 27250 Da. Compared with its human counterpart, rat 17betaHSD type 10 shows 88% identity. Mouse 17betaHSD type 10 is composed of 261 amino acid residues with a calculated molecular mass of 27274 Da. There is 95% identity between the two rodent enzymes. A stereostructure model of rat 17betaHSD type 10 was constructed based on its amino acid sequence. Similar to human type 10 17betaHSD, the rodent enzymes also displayed relatively higher 3alphaHSD activity than 17betaHSD activity. Intracellular localization of rat 17betaHSD type 10 has been determined by subcellular fractionation and confocal microscopy studies. The results unequivocally establish that this is a nuclear gene-encoded mitochondrial enzyme, and that this 17betaHSD is not associated with the endoplasmic reticulum. The unique location distinguishes type 10 from other types of 17beta-hydroxysteroid dehydrogenases.

17-Hydroxysteroid Dehydrogenases↗
PubMed2001

Delta 3,5,delta 2,4-dienoyl-CoA isomerase is a multifunctional isomerase. A structural and mechanistic study.

Delta(3,5),Delta(2,4)-Dienoyl-CoA isomerase (DI), an auxiliary enzyme of unsaturated fatty acid beta-oxidation, was purified from rat mitochondria and peroxisomes and subjected to N-terminal sequencing to facilitate a mechanistic study of this enzyme. The mature mitochondrial DI from rat heart was lacking its 34 N-terminal amino acid residues that have the properties of a mitochondrial targeting sequence. The peroxisomal isomerase was identified as a product of the same gene with a truncated and ragged N terminus. Expression of the cDNA coding for the mature mitochondrial DI in Escherichia coli yielded an enzyme preparation that was as active as the native DI. Because the recombinant DI also exhibited Delta(3,5,7),Delta(2,4,6)-trienoyl-CoA isomerase (TI) activity, both isomerases reside on the same protein. Mutations of any of the 3 acidic amino acid residues located at the active site (Modis, Y., Filppula, S. A., Novikov, D. K., Norledge, B., Hiltunen, J. K., and Wierenga, R. K. (1998) Structure 6, 957-970) caused activity losses. In contrast to only a 10-fold decrease in activity upon replacement of Asp(176) by Ala, substitutions of Asp(204) by Asn and of Glu(196) by Gln resulted in 10(5)-fold lower activities. Such activity losses are consistent with the direct involvement of these latter two residues in the proposed proton transfers at carbons 2 and 6 or 8 of the substrates. Probing of the wild-type and mutants forms of the enzyme with 2,5-octadienoyl-CoA as substrate revealed low Delta(2),Delta(3)-enoyl-CoA isomerase and Delta(5),Delta(4)-enoyl-CoA isomerase activities catalyzed by Glu(196) and Asp(204), respectively. Altogether, these data reveal that positional isomerizations of the diene and triene are facilitated by simultaneous proton transfers involving Glu(196) and Asp(204), whereas each residue alone can catalyze, albeit less efficiently, a monoene isomerization.

Acyl Coenzyme A↗
PubMed2001

[Epiluminescent microscopy aspects of initial cutaneous melanoma metastases].

BACKGROUND AND OBJECTIVE: Especially small and initial cutaneous melanoma metastases (CMMs) are tumours with inconspicuous clinical and sometimes histological features which may be difficult to differentiate from other melanocytic lesions. The present study was performed to determine whether epiluminescence microscopic (ELM) criteria could increase the accuracy in preoperative evaluation of CMMs. PATIENTS/METHODS: Thirty photographed and histologically verified CMMs were examined retrospectively using ELM in order to visualize a multitude of morphological features permitting the recognition of malignancy. The colour slides obtained by the photography were subjected to a secondary 30-80 fold magnification in order to conduct a visual analysis. The 50 naevi in the control group were all histologically benign. RESULTS: Five of the 15 features studied were shown to differ significantly between the two groups. Polymorphic angiectatic base pattern and vascular aneurysms, areas of polymorphic and horizontally dilated capillaries, peripheral erythema, saccular pattern and a light brown halo had a specificity of 90-98% and a sensitivity of 40-46% for CMMs (p<0.001). Peripheral grayish patches, lesions surrounded by gray streaks and microscopic ovoid blood lakes were absent in the benign group. CONCLUSIONS: The prevalence of distinct ELM criteria in CMMs enhances the diagnostic accuracy of malignancy in melanocytic skin lesions.

Color↗
PubMed2001

[Correlation between histopathology and epiluminescent microscopy in nonmelanocytic skin lesions].

Epiluminescence microscopy techniques make surface and subsurface structures accessible to visual examination in vivo. The visualization of a multitude of special morphological features, such as blood vessels, adnexa and deposits of pigments in normal and pathologically changed skin allows a reproducible and topographical stratification. There is a chance of identifying the architecture of the stratum corneum, the epidermis and the papillary bodies. Changes in the amount of melanin can be individually assessed in the stratum corneum and the deeper layers extending into the upper dermis. It is possible to differentiate the orientation, size and color of the blood vessels of the cutaneous vascular plexus, involving the capillaries of the stratum papillare and the subpapillary plexus.

Equipment Design↗
PubMed2001

Non-destructive NIR-FT-Raman analyses in practice. Part I. Analyses of plants and historic textiles.

Non-destructive analysis of natural substances in plants as well as of old dyed textiles by Raman spectroscopy has not been possible using conventional techniques. Exciting lines from the visible part of the spectrum produced photochemical and thermal decomposition of the objects as well as strong fluorescence. Using Nd:YAG laser excitation at 1,064 nm together with a special sample arrangement and interferometric recording, various polyacetylenes in Aethusa cynapium and in chamomile (Chamomilla recutita) and the main valuable substances in gentian species (Gentiana lutea and G. punctata), curcuma roots (Curcuma longa), cinnamon (Cinnamomum zeylanicum), fennel (Foeniculum vulgare), clove (Caryophyllus aromaticus), and ginger (Zingiber officinale) were analyzed non-destructively and discussed in comparison with the corresponding pure standard compounds. We further analyzed non-destructively the FT Raman spectra of collections of historical textiles and lakes used for dyeing. It is possible to distinguish the main dye component non-destructively by using Raman bands.

Biological Factors↗
PubMed2001

Expression of MUC5AC apomucin in transitional cell carcinomas of the urinary bladder and its possible role in the development of mucus-secreting adenocarcinomas.

The histogenesis of primary nonurachal mucus-producing adenocarcinomas of the urinary bladder including signet ring cell carcinomas remains to be elucidated, since the normal bladder contains neither columnar nor mucus-secreting glandular epithelium. Based upon the assumption that adenocarcinomas may develop secondarily from pre-existent transitional cell carcinomas (TCC) by a metaplastic process, it was the purpose of the current immunohistochemical study to analyze whether urothelial carcinomas are capable of secreting MUC5AC apomucin, using the monoclonal antibody 45MI. This antibody has been initially demonstrated to strongly react with the mucus-producing columnar cells of the surface gastric epithelium, recognizing a specific epitope located on the peptide core of glycoproteins as major components of mucins. Nine of 64 uniformly differentiated papillary (14.1%) and 5 of 66 nonpapillary (solid) TCC with a uniform urothelial differentiation (7.6%) expressed the MUC5AC antigen, yielding an overall incidence of 10.8%. Transitional cell carcinomas with a focally altered cellular and structural differentiation (squamous cell, pseudoglandular, true glandular and mixed differentiation) stained positively in a substantially higher percentage of 43.8% (21 of 48 cases). A positive immunoreactivity was also observed in 3 of 19 mixed transitional cell and nonurothelial carcinomas. The tumor-associated resurgence of normally cryptic MUC5AC antigenic determinants in transitional cell carcinomas is considered as a re-expression of oncofetal antigenicity, probably as a result of the embryologic origin of the urinary bladder from the pluripotent tissues of the cloacal endoderm and the mesodermal wolffian ducts. Our findings may help to better understand the histogenetic development of mucus-secreting vesical adenocarcinomas from pre-existent urothelial carcinomas.

Adenocarcinoma, Mucinous↗
PubMed2001

Nitrogen isotope ratios in pine bark as an indicator of N emissions from anthropogenic sources.

The article describes the use of Scots pine bark to identify nitrogen sources in eastern Germany, as well as background areas in Russia and Bulgaria, by using natural isotope ratios of total nitrogen (Nt) and individual N compounds such as ammonium (NH4+), nitrate (NO3-) and amid nitrogen (amide-N). The samples collected were analysed using an elemental analyser in connection with a gas isotope mass spectrometer (EA-IRMS). Natural 15N abundances in pine bark from impact areas suggest that the ammonium accumulated on the surface of the bark is released from livestock management. Bark of Scots pines growing near agricultural land had highly depleted delta15Nt values (between -8 and -12 one thousand percent), while bark from background areas (unpolluted areas) displayed slightly negative delta15Nt values (mean 15Nt = -3.8 one thousand percent). It is assumed that part of the N adsorbed on the bark surface is mainly derived from ammonia (mean 15Nt = -40.3 one thousand percent) escaping from livestock housing and during the application of manure. This assumption is confirmed by experiments under controlled conditions in which manure samples were spread on soil. In addition, temporal and spatial variations of 15Nt abundances in pine bark from various locations in eastern Germany as well as pine stands in Nature Park Dübener Heath are discussed.

Agriculture↗
PubMed2001

Impact of the intramitochondrial enzyme organization on fatty acid oxidation.

The enzymes of mitochondrial beta-oxidation are thought to be organized in at least two functional complexes, a membrane-bound, long-chain-specific beta-oxidation system and a matrix system consisting of soluble enzymes with preferences for medium-chain and short-chain substrates. This hypothesis is supported by the observation that the inactivation of long-chain 3-ketoacyl-CoA thiolase by 4-bromotiglic acid (4-bromo-2-methylbut-2-enoic acid) causes the complete inhibition of palmitate beta-oxidation even though 3-ketoacyl-CoA thiolase, which acts on 3-ketopalmitoyl-CoA, remains partly active. The observed substrate specificities of long-chain acyl-CoA dehydrogenase (LCAD) and very-long-chain acyl-CoA dehydrogenase prompt the suggestion that LCAD is a functional component of the long-chain-specific beta-oxidation system. Altogether, a view is emerging of the organization of beta-oxidation enzymes in mitochondria that supports the idea of intermediate channelling and explains the apparent absence of true intermediates of beta-oxidation from mitochondria.

Acyl-CoA Dehydrogenase↗
PubMed2001

Characterization and localization of human type10 17beta-hydroxysteroid dehydrogenase.

The tissue distribution, subcellular localization, and metabolic functions of human 17beta-hydroxysteroid dehydrogenase type 10/short chain L-3-hydroxyacyl-CoA dehydrogenase have been investigated. Human liver and gonads are abundant in this enzyme, but it is present in only negligible amounts in skeletal muscle. Its N-terminal sequence is a mitochondrial targeting sequence, but is not required for directing this protein to mitochondria. Immunocytochemical studies demonstrate that this protein, which has been referred to as ER-associated amyloid beta-binding protein (ERAB), is not detectable in the ER of normal tissues. We have established that protocols employed to investigate the subcellular distribution of ERAB yield ER fractions rich in mitochondria. Mitochondria-associated membrane fractions believed to be ER fractions were employed in ERAB/Abeta-binding alcohol dehydrogenase studies. The present studies establish that in normal tissues this protein is located in mitochondria. This feature distinguishes it from all known 17beta-hydroxysteroid dehydrogenases, and endows mitochondria with the capability of modulating intracellular levels of the active forms of sex steroids.

17-Hydroxysteroid Dehydrogenases↗
PubMed2001

Cognitive dysfunction in sleep disorders.

Fifty-six studies were reviewed that explored cognitive dysfunctions in people with sleep-related breathing disorders (SRBD, 24 studies), insomnia (18 studies), or narcolepsy (14 studies). Individual study outcomes were grouped according to neuropsychological functions. Available evidence was reviewed separately for SRBD, insomnia and narcolepsy. Consistent evidence was found for impaired driving simulation performance in SRBD patients (92.9% of comparisons with control subjects). Other neuropsychological functions with less pronounced impairment included (i) attention span, divided attention and sustained attention for SRBD patients; (ii) attention span, verbal immediate memory and vigilance for insomniac patients, and (iii) sustained attention, vigilance and driving simulation performance for narcoleptic patients. Reduced performance in tasks measuring attention was found to be higher for SRBD and narcoleptic patients (35.9% and 44.2% of all comparisons, respectively) while this rate was lower for insomniac patients (22.8%). Impairment of memory performance in comparison with control subjects was less pronounced for all three groups, with 20.0% for insomnia, 17.1% for SRBD and 15.6% for narcolepsy. In other areas of cognitive functioning, the data did not allow definite conclusions for any of the patient groups.

Journal Article↗