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Biomedical subjects

E Wagner

Publications and source records attributed to E Wagner.

At least 127 records · Page 7Linked to original sources
PubMed1998

Decisive diagnosis of seronegative polyarthritis by 3-phase bone scintigraphy.

Inflammatory joint disease is mainly diagnosed on grounds of clinical investigation, laboratory testing (acute phase reactants), and radiography. Radionuclide imaging has recently been added to the armamentarium of clinician. This case report points out the role of three-phase bone scan and HIG (human immunoglobulin) scan in the discovery of the inflammatory nature of polyarthralgia in a young woman with equivocal clinical and laboratory results. In the aim of diagnosing arthritis early in its course scintigraphy proved to be superior to conventional radiography. It also allows more discriminating selection of subsequent X-ray examination to limit radiation exposure.

Acute-Phase Proteins↗
PubMed1997

Structure, catalysis and supramolecular assembly of adenylate kinase from maize.

The crystal structure of adenylate kinase from maize ligated with an inhibitor has been determined by molecular replacement and refined to 3.5-A resolution. The enzyme keeps the ATP/ADP/AMP equilibrium in the cell. In the C4 plant maize, it has the special task to recycle the AMP produced in large amounts in primary CO2 assimilation. The established structure explains the side reaction with CMP. Moreover, it shows infinite rods that can be readily discerned in the crystal packing. In comparison with homologues, two structural differences that are crucial for this supramolecular assembly are evident. We propose that the rods represent a natural inactive storage form that assembles at night when maize stops CO2 assimilation and thus most of the AMP production in its C4 cycle. The enzyme is particularly abundant in mesophyll chloroplasts, where such an assembly would release appreciable amounts of water that can be used in other processes during the night.

Adenylate Kinase↗
PubMed1997

Stabilization of gene delivery systems by freeze-drying.

Freeze-drying of three different forms of gene delivery systems was performed using a controlled two-step drying process and 10% sucrose as lyoprotectant. Complexes of pCMVL plasmid with transferrin-conjugated polyethylenimine, adenovirus-enhanced transferrinfection consisting of pCMVL/transferrin-polylysine complexes linked to inactivated adenovirus particles, and a recombinant, E1-defective adenovirus expressing a luciferase reporter gene were tested. Three weeks after freeze-drying the reagents were rehydrated with water and tested for transfection activity. Luciferase gene expression levels were retained at high levels in all three systems, in contrast to reagents stored in solution. The use of the lyoprotectant was essential. In the absence of sucrose the transfection activities dropped by a factor of 100-1000. The data suggest freeze-drying as a useful method for stabilization and storage of standardized batches of transfection agents.

Journal Article↗
PubMed1997

Inappropriate retinoic acid receptor-beta expression in oral dysplasias: correlation with acquisition of the immortal phenotype.

Retinoids are useful in the treatment of premalignant oral lesions and in preventing the occurrence of second primary cancers after resection of the initial primary oral cancer, but long-term prognosis is still poor, presumably due to malignant cells escaping retinoid control. Previous work has shown that loss of expression of retinoic acid receptor beta is one of the most consistent molecular changes during oral cancer progression in vivo. In this report we demonstrate, using a novel panel of primary cultures of oral lesions, that loss of retinoic acid receptor beta expression at the dysplasia stage occurs during the transition from senescent to immortal phenotype but may occur independently to the loss of CDKN2A/p16 expression.

Carrier Proteins↗
PubMed1997

Mice with genetic gamma-glutamyl transpeptidase deficiency exhibit glutathionuria, severe growth failure, reduced life spans, and infertility.

A mouse mutant with glutathionuria was discovered by screening for amino acidurias in the progeny of ethylnitrosourea-mutagenized mice. Total glutathione concentration was increased in both blood and urine but decreased in liver homogenates from affected mice. Glutathionuric mice exhibited lethargy, severe growth failure, shortened life spans and infertility. gamma-Glutamyl transpeptidase activity was deficient in kidney homogenates of glutathionuric mice. The glutathionuric phenotype in these mice is inherited as an autosomal recessive trait. This mouse mutant will be a useful animal model for the study of gamma-glutamyl transpeptidase physiology and glutathione metabolism.

Animals↗
PubMed1997

Glycerol and polylysine synergize in their ability to rupture vesicular membranes: a mechanism for increased transferrin-polylysine-mediated gene transfer.

The presence of about 1.2 M glycerol during transfection with DNA/transferrin-polylysine and DNA/polylysine complexes dramatically increases transgene expression in a variety of cell types, provided that the complexes have an excess of polylysine. We have characterized this phenomenon using a human melanoma cell line (H225). The addition of 1.2 M glycerol to the transfection medium has no influence on the internalization of DNA complexes or on the promoter activity used to direct reporter gene expression. Neither prenor postincubation of the cells with glycerol results in a notable increase in transgene expression. Bafilomycin A1 and chloroquine, two drugs affecting the endosomal pathway, both influenced transgene expression, indicating that glycerol acts on internal vesicles. Glycerol and polylysine synergized in their ability to lyse erythrocytes as well as internal vesicles (microsomes) isolated from H225 cells, indicating that the glycerol effect is due to a labilization of vesicular membranes, which facilitates membrane disruption by polylysine. Our current model suggests that the excess of polylysine in the DNA complexes disrupts vesicular membranes in the presence of glycerol, thus allowing the release of DNA complexes into the cytoplasm.

Anti-Bacterial Agents↗
PubMed1997

Increased accumulation of the glycoxidation product N(epsilon)-(carboxymethyl)lysine in human tissues in diabetes and aging.

N(epsilon)-(Carboxymethyl)lysine (CML), a major product of oxidative modification of glycated proteins, has been suggested to represent a general marker of oxidative stress and long-term damage to proteins in aging, atherosclerosis, and diabetes. To investigate the occurrence and distribution of CML in humans an antiserum specifically recognizing protein-bound CML was generated. The oxidative formation of CML from glycated proteins was reduced by lipoic acid, aminoguanidine, superoxide dismutase, catalase, and particularly vitamin E and desferrioxamine. Immunolocalization of CML in skin, lung, heart, kidney, intestine, intervertebral discs, and particularly in arteries provided evidence for an age-dependent increase in CML accumulation in distinct locations, and acceleration of this process in diabetes. Intense staining of the arterial wall and particularly the elastic membrane was found. High levels of CML modification were observed within atherosclerotic plaques and in foam cells. The preferential location of CML immunoreactivity in lesions may indicate the contribution of glycoxidation to the processes occurring in diabetes and aging. Additionally, we found increased CML content in serum proteins in diabetic patients. The strong dependence of CML formation on oxidative conditions together with the increased occurrence of CML in diabetic serum and tissue proteins suggest a role for CML as endogenous biomarker for oxidative damage.

Adult↗
PubMed1997

Hungarian multicentre epidemiologic study of the warning and initial symptoms (prodrome, aura) of epileptic seizures.

We carried out a Hungarian multicentre study to assess the frequency of the occurrence of warning symptoms preceding epileptic seizure. The data of 562 patients with epilepsy out of a total of 1124 were analysed on the basis of questionnaires filled in under standard conditions. About 50% of the patients experienced warning symptoms before a smaller or greater part of their seizures. Their appearance was fairly consistent and became mainly manifested in the form of headache, epigastric sensation and dysphoria. In relation to epileptological basic data, it was found that warning symptoms appeared primarily in focal epilepsies and among them they mainly preceded generalized tonic clonic and complex partial seizures. Between the warning symptom and the onset of the seizure there was usually a longer interval during which (and generally also during the warning symptom) the patient remained able to act. About 20% of the patients enrolled in the study tried to inhibit the onset or mitigate the course of the seizure and about 10% judged their spontaneous activity carried out in that direction to be successful. The frequency of the occurrence of independent prognostic symptoms not followed by a seizure was relatively low, and among epileptics with warning symptoms the incidence of seizures occurring without a preceding event was not high either. Based on our experiences, we have drawn the conclusion that, in a significant part of epileptic patients, the warning symptoms render possible the supplementation of the therapy by the development of seizure-inhibiting or seizure-avoiding behaviour or activity.

Adolescent↗
PubMed1997

In vitro targeting and specific transfection of human neuroblastoma cells by chCE7 antibody-mediated gene transfer.

We developed a new vector for gene targeting of neuroblastoma (NB) cells, based on the utilization o a monoclonal antibody (chCE7) covalently linked to polylysine (PL). In the presence of chloroquine, chCE7-PL-DNA complexes transfected NB cells as efficiently as DOTAP, transfectam, TF-X50, or lipofectamine. This was demonstrated by transfection of the luciferase or beta-galactosidase reporter genes in three different NB cell lines. This transfection was specific, since it was inhibited in the presence of competing unconjugated chCE7 antibody (Ab), and was not observed in cell lines negative for the CE7 antigen. We tested the potential biological activity of a plasmid coding for gamma-interferon (gamma IFN) transfected with chCE7-PL. HLA ABC expression on NB cells was induced after transfection with pCMV-gamma IFN at a higher level than after incubation with 1000 IU/ml of purified gamma IFN. Moreover, these HLA ABC-positive NB cells were able to activate autologous cytotoxic T lymphocytes in vitro. Thus chCE7-PL is able to target a plasmid to NB cells and to allow the expression of the transfected gene in a biologically active form.

Antibodies, Monoclonal↗
PubMed1997

Lymphocyte apoptosis: induction by gene transfer techniques.

Efficient gene transfer of lymphocytes has been shown to be extremely difficult. The molecular background for this gene transfer resistance is not completely understood. We reasoned that apoptosis may play a role in this gene transfer resistance of lymphocytes. We show that transfection of lymphocytes via nonviral vectors leads to induction of apoptosis in a significant proportion of cells. Since apoptosis may be mediated via the TNF alpha and TNF alpha receptor pathway, we studied the amount of TNF secreted by transfected lymphocytes. The percentage of apoptotic lymphocytes correlated well with TNF alpha secretion. TNF secretion was dependent on the gene transfection method used. High amounts of TNF secretion were detected using receptor-mediated gene transfer and lipofection. In contrast, only low amounts of TNF were detected after electroporation and retroviral gene transfer. In receptor-mediated gene transfer, TNF secretion was due to the use of anti-CD3 antibody. Induction of apoptosis and increase in necrosis was blocked using an anti-TNF antibody. This blockage led to a significant increase in the proliferation rate of lymphocytes transfected with the interleukin-2 or interleukin-7 gene. In conclusion, gene transfer techniques led to TNF secretion, apoptosis and necrosis of lymphocytes. This could be blocked using an anti-TNF antibody. Blockage of apoptosis after gene transfer should have an impact on the use of lymphocytes transfected with cytokine genes as immunologic effector cells in cancer gene therapy protocols.

Antibodies, Monoclonal↗
PubMed1997

Coupling of cell-binding ligands to polyethylenimine for targeted gene delivery.

Recently the high transfection potential of the cationic polymer polyethylenimine (PEI) was described (Boussif O et al. Proc Natl Acad Sci USA 1995; 92: 7297-7301). To combine the promising DNA delivering activity of PEI with the concept of receptor-mediated gene delivery, cell-binding ligands (transferrin or antiCD3 antibody) were incorporated by covalent linkage to PEI. DNA complexes of PEI or ligand-PEI conjugates were tested for transfection of cultured neuroblastoma Neuro 2A cells, melanoma B16 or H225 cells, erythroid leukemic K562 cells and T cell leukemia Jurkat E6.1 cells. Depending on the cell line, incorporation of the cell-binding ligand resulted in an up to 1000-fold increased transfection efficiency. This activity depends on ligand-receptor interaction and was observed also at low PEI cation:DNA anion ratios where ligand-free PEI lacks efficiency. Depending on the cell-binding ligand, specific targeting (CD3 antibody, Jurkat cells) can be achieved. Gene transfer can be augmented by the addition of an endosome-destabilizing influenza peptide, but is not dependent on the presence of additional endosomolytic agents. Application of transferrin-PEI for the production of murine interleukin-2 in B16 cells resulted in exceptionally high secretion rates of 19 micrograms IL-2 protein per 10(6) cells per 24 h.

Animals↗
PubMed1997

Retinoic aid increases arrestin mRNA levels in the mouse retina.

Arrestin, which plays a role in the termination of the visual transduction cascade, is one of several photoreceptor proteins whose mRNA levels are increased by light. Retinoic acid, a by-product of photoreceptor signaling and a potent modulator of hormonal transcription control, is one candidate for regulating the arrestin mRNA levels. Here we show that retinoic acid, injected intraperitoneally into dark-adapted mice, increases the arrestin mRNA levels and mimics the effect of light. Injection of 1 mumol of retinoic acid produces a maximal increase in arrestin mRNA levels. The mRNA level reaches a maximum 3 h after injection and slowly declines thereafter. The observations suggest that retinoic acid may mediate the increase in arrestin mRNA produced by light.

Adaptation, Physiological↗
PubMed1997

Increased serum levels of soluble CD44-isoform v5 in rheumatic diseases are restricted to seropositive rheumatoid arthritis.

Serum levels of sCD44v5 were measured in 134 patients with definite inflammatory rheumatic diseases (IRD) using a sandwich type ELISA. 94 patients suffered from erosive IgM-rheumatoid factor positive rheumatoid arthritis (RA+), 20 with undifferentiated seronegative polyarthritis, 12 with osteoarthropathia psoriatica and psoriasis vulgaris, 3 with systemic lupus erythematosus, 3 with scleroderma and 2 with reactive arthritis. Elevated serum levels (> 58 ng/ml to 221 ng/ml; median: 93 ng/ml) were only detected in 54/94 (57%) patients with RA+, but not in other IRD. They correlated with advanced stages of disease (Steinbrocker stages III + IV; p < 0.05), elevated CRP-levels (p < 0.01) and higher measurements of IgM rheumatoid factor.

Adult↗
PubMed1997

[Sex offenders in legal treatment and their relatives: results of family therapy sessions].

Members of the family of origin and spouses have been invited to take part in a cognitive-behavioral treatment programme for incarcerated sexual offenders to support the offender. Offenders arranged appointments with their spouses, mother, fathers and the therapist. A one-year follow-up reveals considerable change in denying and minimisation of responsibility, forcefullness and degree of sexual intrusiveness of both the offenders and the spouses. Both groups showed a better understanding for and a more positive attitude to the offenders' sexuality. Furthermore, both groups showed a significant increase in applying concepts of relapse prevention.

Adult↗
PubMed1996

Functional Re-expression of laminin-5 in laminin-gamma2-deficient human keratinocytes modifies cell morphology, motility, and adhesion.

Herlitz junctional epidermolysis bullosa (H-JEB) is characterized by a reduced adherence of keratinocytes consequent to deficient expression of the extracellular adhesive ligand laminin-5. To complement the genetic defect causing H-JEB, we transferred an eukaryotic cassette expressing the cDNA for the gamma2 chain of laminin-5 into H-JEB keratinocytes in which the expression of the polypeptide is hampered by a homozygous mutation generating a premature termination codon. Transfection using adenovirus-polylysin-transferrin-DNA complexes resulted in a transient synthesis of the recombinant laminin gamma2 chain that associated with the endogenous alpha3 and beta3 chains to form laminin-5 molecules readily deposited on the tissue culture substrate. Furthermore, retroviral-mediated transduction of the gamma2 cDNA yielded persistent expression and polarized secretion of laminin-5. The protein incorporated into the basement membrane produced by the revertant cells inoculated subcutaneously in nude mice. In these transfectants, re-expression of laminin-5 induced changes in cell morphology and reorganization of focal adhesions that assumed the shape and distribution of the counterparts detected in normal keratinocytes. These observations correlated with an enhanced cell-substrate adhesion and a reduced motility of the transfected cells. Our results demonstrate that a restored expression of laminin-5 induces a phenotypic reversion of genetically altered H-JEB keratinocytes and open new perspectives to the analysis of the mechanisms regulating adhesion of epithelial cells.

Animals↗