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E Weber

Publications and source records attributed to E Weber.

At least 37 records · Page 2Linked to original sources
PubMed2001

Characterization and cloning of a major high molecular weight house dust mite allergen (Der f 15) for dogs.

Although house dust mites (HDM(s)) are important elicitors of canine allergy, the low molecular weight molecules defined as major allergens for humans do not appear to be major allergens for dogs. Western blotting of Dermatophagoides farinae (D. farinae) extracts with sera from sensitized dogs showed that the majority of animals had IgE antibodies specific for two proteins of apparent molecular weights of 98 and 109kDa (98/109kDa). The N-terminal sequences of these two proteins were identical, suggesting they were very closely related, and sequencing of internal peptides showed the protein(s) to have homology with insect chitinases. A purified preparation of 98/109kDa proteins elicited positive intradermal skin tests (IDST(s)) in a group of well-characterized atopic dogs sensitized to D. farinae, but not in normal dogs. A rabbit polyclonal antiserum raised against the purified proteins was used to immunoscreen a D. farinae cDNA library. The mature coding region of the isolated chitinase cDNA predicts a protein of 63.2kDa; sequence analysis and glycan detection blotting suggest that the molecule is extensively O-glycosylated. Monoclonal antibodies made against the purified native protein were used to localize the chitinase in sections of whole D. farinae mites. The protein displayed an intracellular distribution in the proventriculus and intestine of the mite, suggesting that it has a digestive, rather than a moulting-related, function. The high prevalence of IgE antibodies to this antigen in canine atopic dermatitis makes it a major HDM allergen for dogs, and the protein has been formally designated Der f 15.

Amino Acid Sequence↗
PubMed2001

Design and synthesis of rhodamine 110 derivative and caspase-3 substrate for enzyme and cell-based fluorescent assay.

N-Octyloxycarbonyl-R110 (1), with enhanced cell penetration and retention properties, was prepared from rhodamine 110. The tetrapeptide substrate N-Ac-DEVD-N'-octyloxycarbonyl-R110 (3) was prepared and shown to be efficiently cleaved by human recombinant caspase-3 and by apoptotic HL-60 cells. This substrate should prove useful in cell-based assays for apoptosis inducers and inhibitors.

Apoptosis↗
PubMed2001

Immunocompetent astrocytes and microglia display major differences in the processing of the invariant chain and in the expression of active cathepsin L and cathepsin S.

The role of astrocytes and microglia as antigen-presenting cells in the brain is still controversial. In this study we have analyzed and compared aspects of the molecular machinery that underlies MHC class II trafficking in immunocompetent astrocytes and microglia. We show that IFN-gamma-stimulated microglia possess active cathepsin L and cathepsin S, and efficiently degrade the invariant chain, unlike IFN-gamma-stimulated astrocytes that express cathepsin L but not cathepsin S. The lack of cathepsin S proves to be dramatic for the antigen-presentation capacity of astrocytes, which is nearly abolished when these cells are stimulated by a combination of IFN-gamma and TNF-alpha. TNF-alpha indeed decreases cathepsin L activity as we show here, leading to alterations in invariant chain processing, and hence in MHC class II trafficking in astrocytes. Cystatin C inhibits cathepsin L activity in astrocytes, but does not regulate cathepsin L and cathepsin S activity in microglia. We therefore identify cathepsin L and cathepsin S as key components in the regulation of the immune potential of astrocytes and microglia, and provide evidence for a cell-specific regulation exerted by IFN-gamma and TNF-alpha on the expression and activity of cathepsins.

Antigen Presentation↗
PubMed2001

Cathepsin S and an asparagine-specific endoprotease dominate the proteolytic processing of human myelin basic protein in vitro.

The biochemical characterization of antigen degradation is an important basis for a better understanding of both the immune response and autoimmune diseases mediated by MHC class II molecules. In this study we used high-performance liquid chromatography and mass spectrometry to analyze the processing of myelin basic protein (MBP), a potential autoantigen implicated in the pathogenesis of multiple sclerosis. We resolved the kinetics of MBP processing by lysosomal extracts or purified endocytic proteases, identified the major cleavage sites during this process and assigned them to the activity of proteolytic enzymes. Proteolytic processing of MBP is mostly guided along the hydrophobic regions of the protein. It is initiated by two proteolytic steps (after N(92) and S(110)) that are performed by an asparagine-specific endopeptidase (AEP) and by cathepsin (Cat) S, respectively. The resulting processing intermediates are converted into more than 60 different species of 20-40-mers due to the activity of endopeptidases including CatS, D and L. The fragments thus generated are subsequently degraded by C- or N-terminal trimming. Strikingly, the initial cleavages during MBP processing affect two immunodominant regions of the potential autoantigen [MBP(85-99) and MBP(111-129)] in an inverse manner. CatS directly generates the N terminus of the epitope MBP(111-129) in large quantities during the initial phase of processing, which might explain the immunogenicity of this region in spite of its relatively poor binding to HLA-DR4. In contrast, the dominant cleavage by AEP mediates the destruction of MBP(85-99) unless the epitope is protected, e.g. by binding to HLA-DR. Our results thus characterize the proteolytic events during processing of MBP on a molecular level and suggest a biochemical basis for the immunogenicity of the immunodominant epitopes, which could serve as a guideline for future therapeutic strategies.

Amino Acid Sequence↗
PubMed2001

Cathepsin K--a marker of macrophage differentiation?

Cathepsin K is a cysteine protease with high matrix-degrading activity. Initially, cathepsin K was described as being expressed exclusively by osteoclasts. It was suggested that cathepsin K expression is a specific feature of cells involved in bone remodelling. The aim of this study was to investigate the hypothesis that cathepsin K is expressed not only in bone-resorbing macrophages, but also more generally in specifically differentiated macrophages, such as epithelioid cells and multinucleated giant cells in soft tissues. Specimens obtained from different organs and anatomical locations of patients suffering from sarcoidosis, tuberculosis, granulomas caused by foreign materials, and sarcoid-like lesions were investigated for the expression of cathepsins B, K, and L. Immunohistochemistry and in situ hybridization showed cathepsin K in epithelioid cells and multinucleated giant cells irrespective of the pathological condition and anatomical location, but not in normal resident macrophages. By immunoelectron microscopy, cathepsin K was discovered in cytoplasmic granules of multinucleated giant cells. In contrast, cathepsin B and cathepsin L were expressed ubiquitously in CD68-positive tissue macrophages, epithelioid cells, and multinucleated giant cells. The results demonstrate that cathepsin K, but not cathepsin B or cathepsin L, differentiates specific phenotypes of macrophages independently of the anatomical site. Its enzymatic characteristics, particularly its high matrix-degrading activity, suggest that cathepsin K-positive epithelioid cells and multinucleated giant cells are characterized by an enhanced specific proteolytic capability.

Adult↗
PubMed2001

Automated examination notification of emergency department images in a picture archiving and communication system.

This study compares the timeliness of radiology interpretation of Emergency Department (ED) imaging examinations in a picture archiving and communication system (PACS) before and after implementation of an automated paging system for notification of image availability. An alphanumeric pager for each radiology subspecialty (chest, pediatrics, bone, neuroradiology, and body) was used to alert the responsible radiologist that an ED imaging examination is available to be viewed on the PACS. The paging system was programmed to trigger off of the PACS database when an image is received on the appropriate radiology display station. The pager message includes the radiology accession number and examination description (such as chest, two-view, or c-spine, etc). The PACS paging tool performance was assessed by calculating the time elapsed, for each ED imaging examination, from the Time Imaged to the Time of Interpretation, where the Time Imaged is the actual image completion time measured at the imaging modality, and the Time Interpreted is the time a radiology interpretation is rendered to the ED, and is measured from the Radiology-to-ED fax time stamp. These measures were analyzed pre- and post-paging system implementation to determine any impact of the automated notification tool on radiology service turnaround time. Results show an improved radiology response time from image completion to interpretation rendered to ED clinicians, down from hour(s) to minutes, with the automated paging examination notification system. Examinations are read by the appropriate radiology specialty section in a more timely fashion, and fewer cases go unread by radiology.

Emergency Service, Hospital↗
PubMed2001

Forest ecosystem development in post-mining landscapes: a case study of the Lusatian lignite district.

The restoration of surface mining landscapes requries the (re)creation of ecosystems. In Lusatia (eastern Germany), large-scale open-cast lignite mining operations generated spoil dumps widely consisting of acidified, phytotoxic substrates. Amelioration and rehabilitation measures have been developed and applied to these substrates since the 1950s. However, it is still not clear whether these approaches are sustainable. This paper reports on collaborative research work into the ecological potential of forest ecosystem development on typical minesites in the Lusatian lignite district. At first sight, pine stands on minesites along a chronosequence comprising about 35 years did not show differences when compared with stands on non-mined sites of the general region. Furthermore, with some modification, conceptual models for flora and fauna succession in forest stands on non-mined sites seem to be applicable, at least for the early stages of forest ecosystem development. For example, soil organism abundance and activity at minesites had already reached levels typical of non-mined sites after about 20-30 years. In contrast, mine soils are very different from non-mined soils of the test region. Chemically, mine soil development is dominated by processes originating from pyrite oxidation. Geogenic, i.e. lignitic, soil organic carbon was shown to substitute for some functions of pedogenic soil organic matter. Rooting was hampered but not completely impeded in strongly acidified soil compartments. Roots and mycorrhizae are apparently able to make use of the characteristic heterogeneity of young mine soils. Considering these recent results and the knowledge accumulated during more than 30 years of research on minesite rehabilitation internationally, it can be stated that minesite restoration might be used as an ideal case study for forest ecosystem development starting at "point zero" on "terra nova".

Coal Mining↗
PubMed2001

Synthesis and SAR of 5-, 6-, 7- and 8-aza analogues of 3-aryl-4-hydroxyquinolin-2(1H)-one as NMDA/glycine site antagonists.

A series of 5-, 6-, 7- and 8-aza analogues of 3-aryl-4-hydroxyquinolin-2(1H)-one was synthesized and assayed as NMDA/glycine receptor antagonists. The in vitro potency of these antagonists was determined by displacement of the glycine site radioligand [(3)H]5,7-dicholorokynurenic acid ([(3)H]DCKA) in rat brain cortical membranes. Selected compounds were also tested for functional antagonism using electrophysiological assays in Xenopus oocytes expressing cloned NMDA receptor (NR) 1A/2C subunits. Among the 5-, 6-, 7-, and 8-aza-3-aryl-4-hydroxyquinoline-2(1H)-ones investigated, 5-aza-7-chloro-4-hydroxy-3-(3-phenoxyphenyl)quinolin-2-(1H)-one (13i) is the most potent antagonist, having an IC(50) value of 110 nM in [(3)H]DCKA binding and a K(b) of 11 nM in the electrophysiology assay. Compound 13i is also an active anticonvulsant when administered systemically in the mouse maximum electroshock-induced seizure test (ED(50)=2.3mg/kg, IP).

Animals↗
PubMed2001

IL-1 beta- and IL-4-induced down-regulation of autotaxin mRNA and PC-1 in fibroblast-like synoviocytes of patients with rheumatoid arthritis (RA).

Autotaxin (ATX) is a 125-kD ectonucleotide pyrophosphate/phosphodiesterase, which was initially isolated and cloned from human melanoma cells as a potent stimulator of tumour cell motility. ATX shows 44% identity to the plasma cell membrane marker PC-1. Recently, we described the decreased expression of ATX mRNA in cultured fibroblast-like synoviocytes (SFC) of patients with RA by interferon-gamma. In this study using a competitive reverse transcriptase-polymerase chain reaction, we show an increased ATX mRNA expression in SFC from patients with RA in comparison with synoviocytes from non-RA patients. The median ATX mRNA amount in SFC of RA patients (440 pg/microg total RNA) was five-fold higher than the expression in synoviocytes from non-RA patients (80 pg/microg total RNA) or foreskin fibroblasts (MRHF cells, 90 pg/microg total RNA). In contrast to the elevated ATX mRNA expression in SFC of patients with RA, we did not measure increased mRNA amounts of PC-1 in these cells. Both the ATX mRNA amount and the 5'-nucleotide phosphodiesterase (PDE) activity of SFC lysate were reduced after treatment of SFC with the cytokines IL-1beta or IL-4. IL-1beta and IL-4 induced a down-regulation of PC-1 mRNA and protein expression in SFC. In SFC treated with transforming growth factor-beta the expression of PC-1 mRNA and protein was increased, whereas no significant effect on ATX mRNA expression was detectable. Pharmacological drugs used in therapy for RA, such as dexamethasone, cyclosporin, methotrexate and indomethacin, did not show a statistically significant effect on either ATX mRNA or PC-1 mRNA expression. Only pentoxifylline suppressed ATX mRNA as well as PC-1 mRNA expression. In conclusion, we show a tight regulation of ATX and PC-1 gene expression by cytokines detectable in the inflamed tissue of RA. Further investigations will deal with the regulation of ATX protein expression as well as with the function of ATX in RA.

Anti-Inflammatory Agents↗
PubMed2001

Citation characteristics of research published in Emergency Medicine versus other scientific journals.

STUDY OBJECTIVE: We sought to examine how a cohort of published emergency medicine research is cited in scientific journals. METHODS: Data were collected on all research submitted to the 1991 Society for Academic Emergency Medicine meeting and subsequently published. Outcome measures included all citations of these studies found in journals listed in the Science Citation Index, as well as the impact factors (citations per manuscript per year) of citing journals. RESULTS: Two hundred four of the 493 submitted studies were published and met study entry criteria; the average article was cited 2.04 times a year during the study period. Twelve percent were never cited, and 39% were cited only once or twice. Thirty percent were published in non-emergency medicine journals, and these were cited at least twice as often (and by almost 3 times as many journals) as apparently similar studies published in emergency medicine journals. The percentage of studies never cited by anyone was about threefold higher when published in emergency medicine journals. Forty-two percent of the citations of research published in emergency medicine journals came from within the specialty. Emergency medicine journals provided only 16% of the citations of emergency medicine research published in non-emergency medicine journals because these studies were cited 3 times as often by authors in other disciplines. Rejection of research for presentation at the meeting did not predict the number or quality of citations or citing journals. CONCLUSION: Research submitted to the Society for Academic Emergency Medicine meeting and subsequently published is cited about as often as the average scientific journal article but receives more impact, is cited more widely, and is more likely to be cited by a broader range of authors when published by non-emergency medicine journals. The ability of emergency medicine journals to compete with larger non-emergency medicine journals for their larger audiences may help shape perceptions of the specialty.

Emergency Medicine↗
PubMed2001

Canine interleukin-5: molecular characterization of the gene and expression of biologically active recombinant protein.

Interleukin-5 (IL-5), which is produced primarily by type 2 T helper lymphocytes (Th2), is an eosinophil differentiation and activation factor. Increased numbers of eosinophils in peripherial blood or tissues (eosinophilia) are observed in asthmatic human patients, in animals with helminth infections, and in dogs with allergic diseases. Antagonism of IL-5 activity is being explored as a potential treatment of a number of disease conditions associated with eosinophils in animal models. In order to study the expression and function of this cytokine in the dog, we have isolated and characterized the canine IL-5 gene. The canine IL-5 polypeptide deduced from the cDNA is composed of 134 amino acids that share varying degrees of homology with IL-5 isolated from several mammals. The genomic structure of the canine IL-5 gene consists of four exons and three introns in the coding region, similar to that of the previously characterized human and mouse IL-5 genes. Recombinant canine IL-5 protein, expressed in Pichia pastoris, is biologically active in a cell proliferation assay. Canine IL-5 gene sequences and the biologically active protein described in this study will be useful reagents for future studies of this cytokine in physiologic processes and in pathologic conditions of the dog.

Amino Acid Sequence↗
PubMed2001

Growing pains.

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Emergency Medicine↗
PubMed2001

Prevalence and recognition of depressive symptoms among homebound older adults with urinary incontinence.

Within a group of homebound elders with urinary incontinence, the objectives of this study were to (1) examine the prevalence of depressive symptoms, (2) examine the extent to which depression had previously been recognized by health care providers, (3) describe the type and intensity of antidepressant treatment prescribed for subjects, and (4) identify the demographic and functional characteristics associated with depressive symptomatology. A descriptive correlational design was used. The 15-item Geriatric Depression Scale (GDS-15) was administered to 345 homebound adults age 60 years and over referred to a study examining the effectiveness of behavioral therapy for urinary incontinence. Individuals were referred to the study by home care nurses from two large Medicare-approved home health agencies in a large metropolitan county in Pennsylvania. Data were collected during in-home assessments and by chart review. Measures included the GDS-15, structured medical history, in-home review of medications, Older Americans Research and Service Center Physical and Instrumental Activities of Daily Living scales, Mini-Mental State Examination (MMSE), Clock Drawing Test, Performance-Based Toileting Assessment, and bladder diaries. One half of the participants (n = 173; 50.1%) had significant depressive symptomatology, with 35.7% having scores suggesting mild depression and 14.5% severe depression. Only 26.4% and 34.7% of those with mild and severe depressive symptoms, respectively, had a previous diagnosis of depression and only 21.7% and 34.0%, respectively, had been prescribed an antidepressant. The most commonly prescribed class of antidepressants was tricyclic antidepressants, being taken by 9.0% (n = 31) of the total sample, 14 (11.4%) of those with mild symptoms and 4 (8.0%) of those with severe depressive symptomatology. A little over half (60.0%) of subjects being treated with antidepressants continued to exhibit significant depressive symptomatology. Greater dependence in physical activities of daily living, the need for assistance during ambulation, higher MMSE scores, and higher levels of comorbidity were associated (P < .05) with a GDS-15 score of 5 or higher. Depression symptoms are common in homebound older adults with urinary incontinence, but clinical recognition and treatment are limited.

Aged↗
PubMed2001

Splice variants of human cathepsin L mRNA show different expression rates.

Human cathepsin L (hCATL) mRNA occurs in vivo in at least three splice variants. They differ in the length of exon 1, which comprises 278 nucleotides (hCATL-A), 188 nucleotides (hCATL-A2) and 132 nucleotides (hCATL-A3), respectively. We describe here the shortest variant for the first time. This form is predominant in all tissues and cells examined so far, including malignant tumors. We studied the expression rate of the three mRNA variants in order to explain why malignant kidney tumors show low cathepsin L activity despite of high mRNA levels. The variant hCATL-A3 showed the highest expression rate in vitro and in vivo. Based on these results, we suggest a cis-acting element on human cathepsin L mRNA which can be bound by a negative trans-acting regulator, thus leading to reduced expression rates.

Cathepsin L↗
PubMed2001

Recent advances in retrovirus vector-mediated gene therapy: teaching an old vector new tricks.

Oncoretrovirus-based vectors have been shown to be a safe and reliable vector system that can achieve permanent integration of delivered transgenes. Successful application of these vectors for gene therapy has proven difficult due to their relatively low transduction efficiency; however, cumulative improvements in methodology have recently yielded promising clinical results. Furthermore, significant improvements in basic retrovirus vector technology now promise to revitalize the field. This review focuses on these important recent developments in the field of retrovirus-mediated gene transfer technology and its application to human diseases.

Animals↗
PubMed2000

A new organic nanoporous architecture: dumb-bell-shaped molecules with guests in parallel channels

A new type of dumb-bell-shaped host molecule (6-8) has been synthesised, of which 1,8-bis((1)-adamantyl)-1,3,5,7-octatetrayne (8 = BAOT) forms an open porous architecture when cocrystallised with a number of typical solvent molecules. Adamantyl substituents attached to a tetraalkyne spacer build up the walls of parallel channels wherein guest molecules are aligned. Surprisingly, the tetraalkyne unit is significantly bent. Desolvation experiments provide evidence for a reversible inclusion of guests. In the case of the inclusion of 2-butanone, a partial substitution by symmetrical and asymmetrical long-chain chromophores during crystallisation was possible. Stained crystals showed optical frequency doubling. The crystal structure analysis revealed a centric space group, although considerable translational and orientational disorder was present. Application of scanning pyroelectric microscopy revealed that the growth of inclusion compounds with 2-butanone produced polar ordering of guest molecules, which were aligned in two macro-domains of opposing polarity. The resulting orientation of the carbonyl dipoles is in agreement with the theoretical prediction of a Markov model of spontaneous polarity formation based on molecular recognition processes on growing crystal faces. The present case represents a new example of a property-driven supramolecular synthesis.

Journal Article↗
PubMed2000

Cathepsin K expression in human lung.

Tissue remodeling is crucial in different lung diseases, in the embryonal development as well as in bronchial carcinoma. Cathepsins were proposed to be involved in the degradation of matrix proteins. Cathepsin K is one of the most potent matrix-degrading cysteine proteinases known as yet. The elastinolytic and collagenolytic activity of this papain-like protease is comparable with that of neutrophil elastase. We have investigated the cathepsin K expression in normal adult lung tissues, in embryonal lung tissue and in bronchial carcinoma. With help of specific anti-cathepsin K antibodies it could be shown that cathepsin K was expressed in bronchial epithelial cells. These data could be confirmed at mRNA level using a quantitative RT-PCR as well as by visualisation of the specific enzymatic activity in epithelial cell lines. During the embryonal development cathepsin K was expressed in the epithelial cells of the developing bronchi. The expression seemed to be upregulated in parallel with the development of the bronchial and alveolar lumen. In the later phase of lung development the cathepsin K expression was restricted to bronchial epithelial cells. Furthermore, using quantitative RT-PCR it could be shown that cathepsin K-mRNA was upregulated in lung tumor tissues in comparison to normal tissues from the same patients. These data suggest that cathepsin K may play an important role in matrix remodeling of the lung under physiological and pathological conditions.

Bronchi↗