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Biomedical subjects

M Schreiner

Publications and source records attributed to M Schreiner.

At least 19 recordsLinked to original sources
PubMed2007

Interaction between atmospheric CO2 and glucosinolates in broccoli.

Total and individual glucosinolate contents of broccoli cv Marathon were assessed at ambient CO2 (430-480 ppm) and elevated atmospheric CO2 (685-820 ppm) to determine the ecological relationship between changing atmospheric CO2 concentrations and phytochemicals. Elevated atmospheric CO2 concentration had a differing effect on individual glucosinolates and glucosinolate groups. Total glucosinolate content increased at elevated atmospheric CO2 concentration as a result of a strong increase in both methylsulfinylalkyl glucosinolates glucoraphanin and glucoiberin. In contrast, indole glucosinolates simultaneously decreased, predominantly because of a reduction of glucobrassicin and 4-methoxy-glucobrassicin contents. We conclude that changes in N content and N/S ratios as well as alterations in photochemical processes at elevated atmospheric CO2 concentration can influence total and individual glucosinolates contents of Brassicaceae, as demonstrated in the greenhouse, for broccoli.

Atmosphere↗
PubMed2006

Prevention of high-fat diet-induced adipose tissue remodeling in obese diabetic mice by n-3 polyunsaturated fatty acids.

OBJECTIVE: Obesity is associated with reduced insulin sensitivity and extensive reorganization of adipose tissue. As polyunsaturated fatty acids (PUFA) appear to inhibit diabetes development, we investigated PUFA effects on markers of matrix remodeling in white adipose tissue. METHODS AND PROCEDURE: Male obese diabetic (db/db) mice were treated with either a low-fat standard diet (LF), or high-fat diets rich in saturated and monounsaturated fatty acids (HF/S), n-6 PUFA (HF/6) or the latter including marine n-3 PUFA (HF/3). White adipose tissue was analyzed for gene expression, fatty acid composition and by immunofluorescence. RESULTS: HF/S treatment increased adipose tissue expression of a number of genes involved in matrix degradation including matrix metalloproteinase (MMP)-12, -14 and cathepsin K, L and S compared with LF. MMP-12 gene was expressed in macrophages and adipocytes, and MMP-12 protein colocalized with both cell types. In addition, mean adipocyte area increased by 1.6-fold in HF/S-treated mice. Genes essential for collagen production, such as procollagen I, III, VI, tenascin C and biglycan were upregulated in HF/S-treated animals as well. N-3 PUFA supplementation resulted in enrichment of these fatty acids in adipose tissue. Moreover, n-3 PUFA inhibited the HF/S-induced upregulation of genes involved in matrix degradation and production I restored mean adipocyte area and prevented MMP-12 expression in macrophages and adipocytes. CONCLUSION: N-3 PUFA prevent high-fat diet-induced matrix remodeling and adipocyte enlargement in adipose tissue of obese diabetic mice. Such changes could contribute to diabetes prevention by n-3 PUFA in obese patients.

Adipocytes↗
PubMed2004

Statistical evaluation of potash-lime-silica glass weathering.

Two potash-lime-silica model glasses with compositions similar to those of medieval stained glass were exposed at 26 test sites all over Europe and in North America for 3-6 years. The objectives of this large-scale field exposure programme were: (a) a qualitative analysis of the weathering products formed on the surface of the samples in the (environmental) scanning electron microscope in combination with energy dispersive X-ray microanalysis (ESEM/EDX or SEM/EDX, respectively); (b) a statistical evaluation of the weathering phenomena by applying a multiple linear regression (MLR) analysis to find correlations between the degree of weathering, which was measured in terms of surface coverage with reaction products, and environmental parameters such as the concentration (c) of the acidifying gases SO(2), NO(2) and O(3), the temperature (T) and the relative humidity (RH); and (c) the calculation of a time-dependence function of the weathering process of these glasses. Mainly sulfates of calcium and potassium such as gypsum (CaSO(4).2 H(2)O), arcanite (K(2)SO(4)) and syngenite (CaSO(4).K(2)SO(4).H(2)O) could be identified in the SEM and ESEM. Carbonates, nitrates and many particles deposited on the glass surface were found as well. MLR calculations exhibit significant dependencies of the degree of weathering on T, RH, c(NO(x)), c(SO(2)) and c(O(3)). Applying a time-dependence function of the general form y= a. t(b) (t=time) results in a value of approximately 0.42 for the exponent b, which comes close to values expected from various studies in the literature.

Calcium Compounds↗
PubMed2004

Feeding laying hens seal blubber oil: effects on egg yolk incorporation, stereospecific distribution of omega-3 fatty acids, and sensory aspects.

Seventy-two 26-wk-old Single Comb White Leghorn laying hens were randomly assigned to 36 cages (2 per cage) in a 3-orthogonal 4 x 4 latin square, with the fourth row suppressed, to assess the effect of feeding refined seal blubber oil (SBO, containing 22.2% omega-3 fatty acids) on the fatty acid composition and position in the egg yolk lipids. The experiment was conducted over a period of 9 wk. Eggs were collected and numbered, and the weights were recorded for each week and cage. Eggs collected at wk 5 and 9 were used for total lipid, lipid class, fatty acid, and positional analyses. Sensory evaluation was carried out on eggs collected at wk 6 and 7. Feeding SBO at 1.25% led to an increase (P < 0.0001) in the long-chain omega-3 polyunsaturated fatty acids (LCn3PUFA) and a concomitant decrease (P < 0.0001) in arachidonic acid (ARA) in the egg yolk lipids. Yet this amount of SBO in the diet had no effect (P > 0.1) on the sensory attributes of the egg and on production parameters such as egg weight, number of eggs laid, and feed intake (P > 0.05). When feeding SBO in amounts higher than 1.25% proportionately, a plateau effect of the LCn3PUFA content of the eggs was observed. This appears to be because the PUFA content in the sn-2 position of the phospholipids cannot exceed a certain amount. When this amount is reached, the LCn3PUFA will be increasingly stored in triglycerides. The results presented here clearly indicate how eggs can be produced with optimized composition of LCn3PUFA without affecting (P > 0.1) the sensory properties of the eggs. The procedures elaborated herein provide directly applicable consequences for the food industry.

Animals↗
PubMed2003

Design and application of a new cell for in situ infrared reflection-absorption spectroscopy investigations of metal-atmosphere interfaces.

A new experimental setup for studying reactions occurring in the metal-atmosphere interface by applying in situ infrared reflection-absorption spectroscopy (IRRAS) is presented. It consists of a gas-mixing unit, where the moist air is generated with or without corrosive gases, the reaction cell for the in situ investigations, and an optical system coupled with a Fourier transform infrared (FT-IR) spectrometer. For testing the unit, a specimen of pure copper was used, where the growth of Cu2O on the polished surface could be observed during time-resolved measurements in synthetic air containing 80% RH (relative humidity). For comparison of the experimental results obtained, a computer simulation program was developed in order to calculate the peak position, the peak height, the peak width, and the thickness of the surface layer formed during the atmospheric corrosion. The simulation software is based on the four-phase model of covered surfaces.

Atmosphere↗
PubMed2000

Application of a purge and trap TDS-GC/MS procedure for the determination of emissions from flame retarded polymers.

Emissions of volatile organic compounds (VOCs) from different thermoplastic polymers used in electrotechnical applications were investigated using a purge and trap procedure that involved adsorption on Tenax GR. Results were compared to those for an operating TV set monitored in a test chamber. The analyses were in both cases carried out using thermodesorption gas chromatography with mass spectrometric detection (TDS-GC/MS). Substances identified were monomers, volatile additives, or related compounds. Special attention was given to the detection of halogenated compounds. Their origin was studied using reference samples and synthetic standards.

Air Pollutants↗
PubMed2000

Different manifestations of langerhans cell histiocytosis affecting two members of a family.

Two different manifestations of Langerhans cell histiocytosis (histiocytosis X) are presented, the first occurring as a solitary rib eosinophil granuloma in an 11-year-old girl, and the second as an eosinophil granuloma of the lung of her mother, a 41-year-old heavy smoker, appearing 8 years after the onset of her daughter's disease. Familial clustering of two different manifestations of histiocytosis X disease is very rare and raises the possibility of inherited mutations that promote emergence of clonal Langerhans cells.

Adult↗
PubMed1999

Lessons for microenterprise programs from a fresh look at the unemployment insurance self-employment demonstration.

Microenterprise programs aim to foster self-employment among the poor, those on welfare, and the unemployed. The only experimental test of their impact is the Unemployment Insurance Self-Employment Demonstration (UISED). UISED did shorten unemployment spells, but most other impacts were small and the most disadvantaged did not choose to participate. Although UISED provides some weak evidence that long-term income support, long-term work-search waivers, and on-call advice may increase total employment (but perhaps not self-employment) more than capital infusions and up-front classes, UISED does not reveal the best design for microenterprise programs or whether such programs are good social investments.

Adult↗
PubMed1998

Characterization of the F(ab')2 fragment of a murine monoclonal antibody using capillary isoelectric focusing and electrospray ionization mass spectrometry.

We characterized a F(ab')2 fragment obtained by pepsin cleavage from a murine monoclonal IgG3 by means of electrospray ionization (ESI) mass spectrometry (MS), capillary isoelectric focusing (cIEF), high-performance anion-exchange chromatography-pulsed amperometric detection (HPAEC-PAD) and LC-MS peptide mapping. Separation of the fragment by cIEF under nonreducing conditions resulted in a number of distinct peaks. Using reducing conditions the heavy chain and the light chain were separated into two peaks each. Analysis by ESI-MS revealed a high mass heterogeneity of the molecule. Digestion with neuraminidase simplified both the cIEF pattern and the mass spectrum. The cIEF of the reduced molecule showed that the sialic acids were located only on the heavy chain of the F(ab')2-fragment. By incubation with O-glycosidase a further reduction of the complexity of the mass spectrum was achieved showing 8 different isoforms. By LC-MS peptide mapping these isoforms could be attributed to the heterogeneity of the pepsin cleavage site in the hinge region of the antibody. The sugars of the O-linked carbohydrate chain were identified by HPAEC-PAD as galactosyl-N-acetyl-galactosamine (GalNAcGal) with terminal N-glycolylneuraminic acid. The glycosylation site was identified by peptide mapping and amino acid sequence analysis as Ser222.

Amino Acid Sequence↗
PubMed1998

Defective basement membrane in laryngeal carcinomas with heterogeneous loss of distinct components.

In this study, we evaluated immunohistochemically the composition of the tumor-associated epithelial basement membrane (BM) in a series of 66 laryngeal squamous cell carcinomas (SCC) and compared these results with those from 10 cases with laryngeal dysplasia and five cases with normal mucosa (controls). The major BM components collagen IV and VII, laminin-1, perlecan (heparan sulfate proteoglycan), and fibronectin were evaluated. The extent of the retained BM material was quantified by semiautomated morphometry. A subsequent statistical analysis correlated the immunohistochemical findings with the histopathologically evaluated degree of tumor cell differentiation. In our series, we observed a distinct correlation between the degree of tumor cell differentiation and the amount of retained BM material. The loss of BM affected the various components differently, with a more extensive loss of collagen VII even in highly differentiated tumors and a progressive loss of collagen IV immunostaining with decreasing tumor cell differentiation. With respect to the other BM components, a stepwise loss of BM material also was seen with decreasing degree of the tumor cell differentiation. This loss, however was not at a statistically significant level, so these parameters did not show further statistically relevant data. In dysplastic lesions (regardless of the degree of dysplasia), focal BM disruptions were seen that affected the various BM components to a very similar extent. Our observations provide evidence that laryngeal carcinomas show a progressive loss of BM material along with decreasing tumor cell differentiation. This loss of BM, however, affects the various BM components differently. This indicates a dysregulation of the BM, either induced by uncoordinated neosynthesis or selectively enhanced degradation by proteases or both. Finally, the BM analysis may provide information on the biological course of the tumors. The loss of collagen VII may serve as a marker for "early" invasive tumor growth, whereas the amount of collagen IV provides significant information on the loss of tumor cell differentiation.

Adult↗
PubMed1998

Assignment of Tangier disease to chromosome 9q31 by a graphical linkage exclusion strategy.

A low level of high density lipoprotein (HDL) cholesterol is a strong predictor of ischaemic heart disease (IHD) and myocardial infarction. One cause of low HDL-cholesterol is Tangier disease (TD), an autosomal codominant inherited condition first described in 1961 in two siblings on Tangier Island in the United States of America. Apart from low HDL-cholesterol levels and an increased incidence of atherosclerosis, TD is characterized by reduced total cholesterol, raised triglycerides, peripheral neuropathy and accumulation of cholesteryl esters in macrophages, which causes enlargement of the liver, spleen and tonsils. In contrast to two other monogenic HDL deficiencies in which defects in the plasma proteins apoA-I and LCAT interfere primarily with the formation of HDL (refs 7-10), TD shows a defect in cell signalling and the mobilization of cellular lipids. The genetic defect in TD is unknown, and identification of the Tangier gene will contribute to the understanding of this intracellular pathway and of HDL metabolism and its link with IHD. We report here the localization of the genetic defect in TD to chromosome 9q31, using a genome-wide graphical linkage exclusion strategy in one pedigree, complemented by classical lod score calculations at this region in a total of three pedigrees (combined lod 10.05 at D9S1784). We also provide evidence that TD may be due to a loss-of-function defect.

Chromosome Mapping↗
PubMed1997

Quantification of IBZM dopamine receptor SPET in de novo Parkinson patients before and during therapy.

A number of neurodegenerative diseases have been evaluated with 123I-iodobenzamide (123I-IBZM) dopamine receptor scintigraphy, including Parkinson's disease. Differential diagnosis is based on the semi-quantitative determination of striatal uptake in the basal ganglia. Seven procedures for calculating basal ganglia uptake were compared and checked statistically in (1) 28 previously untreated de novo parkinsonian patients before and (2) 14 patients after (mean of 9 months) commencement of anti-Parkinson medication. Of the 21 hemi-parkinsonian patients, 16 demonstrated increased uptake contralaterally (mean right-to-left difference = 8%, sensitivity = 76%) using the most robust uptake procedure. The difference in uptake between the affected and contralateral sides (mean = 6%) was significant (P = 0.02). The mean (+/- S.D.) basal ganglia/frontal cortex (BG/FC) ratio was 1.55 +/- 0.14 (attenuation-corrected). Attenuation correction did not affect the relative ratio of basal ganglia uptake (P = 0.01). The anti-Parkinson medication did not result in any significant changes in the BG/FC ratio at follow-up, but responders could be differentiated from non-responders based on initial uptake (mean BG/FC ratio of 1.58 and 1.39 respectively). We conclude that 123I-IBZM can be used routinely to identify which Parkinson patients will benefit from dopaminergic medication.

Adult↗
PubMed1996

[Angiocentric T-cell lymphoma of the lung].

Angiocentric T-cell lymphoma of the lung. The case history of a patient with primary angiocentric T-cell lymphoma of the lung having an unusually long survival period (> 10 years) is presented. Attention is paid to the possibilities of differential diagnosis that should be taken into account in the analysis of certain lymphocytic infiltrates of the lung. In accordance with relevant data of the literature, this case shows that pleiomorphic small cell T-lymphomas may have a protracted course, and the disease free periods repeatedly achieved in this patient by irradiation and chemotherapy are thought to be noticeable. Authors refer to some recent findings which may give new insights in the pathobiology of extranodal T-cell lymphomas, and result in recognition of new disease entities.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Ultraviolet matrix assisted laser desorption ionization-mass spectrometry of electroblotted proteins.

Direct mass spectrometric analysis of proteins electroblotted onto polyvinylidene fluoride membranes after sodium dodecyl sulfate-polyacrylamide gel electrophoresis is demonstrated by matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) with a linear time-of-flight instrument, equipped with a nitrogen laser (337 nm). The blotted proteins were desorbed directly from the blotting membrane after incubation with sinapinic acid as matrix. Different commercially available membranes resulted in high quality protein signals for hydrophobic membranes exhibiting high specific surface areas (Immobilon PSQ or Trans-Blot) or for charged membranes (Immobilon CD). Systematic investigations with standard proteins were performed to compare standard preparation procedures for ultraviolet (UV) MALDI-MS on stainless steel sample stages and preparation of proteins immobilized onto membranes either by direct application from protein solutions (spotting) or by electrotransfer from gels (electroblotting). Aspects such as mass resolution reproducibility from shot to shot and spot to spot, mass accuracy, and preservation of protein localization are addressed in this paper.

Electrophoresis, Polyacrylamide Gel↗
PubMed1995

Phylogenetic relationship of the green alga Nanochlorum eukaryotum deduced from its chloroplast rRNA sequences.

The marine green coccoidal alga Nanochlorum eukaryotum (N.e.) is of small size with an average diameter of 1.5 microns. It is characterized by primitive-appearing biochemical and morphological properties, which are considerably different from those of other green algae. Thus, it has been proposed that N.e. may be an early developed algal form. To prove this hypothesis, DNA of N.e. was isolated by a phenol extraction procedure, and the chloroplast DNA separated by preparative CsCl density-gradient centrifugation. The kinetic complexity of the nuclear and of the chloroplast DNA was evaluated by reassociation kinetics to 3 x 10(7) bp and 9 x 10(4) bp, respectively. Several chloroplast genes, including the rRNA genes, were cloned on distinct fragments. The order of the rRNA genes corresponds to the common prokaryotic pattern. The 16S rRNA gene comprises 1,548 bases and is separated from the 23S rRNA gene with its 2,920 bases by a short spacer of 460 bases, which also includes the tRNA(Ile) and tRNA(Ala) genes. The 5S rRNA gene has not been found; it must start further than 500 bases downstream from the 3'-end of the 23S rRNA gene. From the chloroplast rRNA sequences, we have deduced secondary structures of the 16S and 23S rRNAs, which are in agreement with standard models. The rRNA sequences were aligned with corresponding chloroplast sequences; phylogenetic relationships were calculated by several methods. From these calculations, we conclude that N.e. is most closely related to Chlorella vulgaris. Therefore, N.e. does not represent an early developed algal species; the primitive-appearing morphological and biochemical characteristics of N.e. must rather be explained by secondary losses.

Chlorella↗
PubMed1994

Dopamine D2 receptor occupancy measured by single photon emission computed tomography with 123I-Iodobenzamide in chronic schizophrenia.

Single photon emission computed tomography (SPECT) with 123I-iodobenzamide (123I-IBZM) was used to study 22 chronic schizophrenic patients. The patients, who were receiving maintenance therapy with typical neuroleptics, had not shown any significant improvement since their admission to the hospital. Basal ganglia/frontal cortex ratios of the uptake of 123I-IBZM did not show significant differences on the basis of neuroleptic dosage in chlorpromazine equivalents. There were, however, significant differences in 123I-IBZM uptake in the basal ganglia among patients characterized by negative, mixed, and positive symptoms of schizophrenia. Although only a small number of patients had shown a positive response to treatment by the time of discharge, D2 receptor blockade was significantly higher in responders than in nonresponders. In addition, there was an inverse correlation between reduced activation as measured by the Brief Psychiatric Rating Scale and the basal ganglia/frontal cortex ratio. These findings suggest a complex pathogenetic link between the blockade of dopamine D2 receptors and psychopathology in chronic schizophrenic patients. SPECT studies with 123I-IBZM appear to have prognostic value in identifying chronic schizophrenic patients who respond poorly to neuroleptic treatment.

Adult↗
PubMed1994

[Immunohistochemical basement membrane analysis of cholesteatoma epithelium].

Cholesteatoma is a disease with an epithelial state of hyperproliferation based on a disturbed cell-matrix interaction. An analysis of the basement membrane, which can modulate epithelial proliferation, reveals a dysfunction of this layer between cholesteatoma and stroma. Cholesteatoma specimens were obtained from six patients undergoing middle ear surgery. Immunohistochemical staining was performed using antibodies against the major components of basement membranes such as laminin, heparan sulfate proteoglycan (HSPG), collagen IV and fibronectin. In cholesteatoma epithelium, we found a fragmented basement membrane with small amounts of laminin and HSPG showing only occasional positively stained fragments while collagen IV was almost completely absent. In contrast, fibronectin demonstrated an intensive staining especially in the stroma adjacent to the basement membrane. This staining pattern resembles the initial rearrangement of the epithelial basement membrane in human skin wounds and provides evidence for a lost contact inhibition on the provisional fibronectin-layer as a reason for the hyperproliferative nature of cholesteatoma lesions.

Basement Membrane↗