PubMed Health⌕ Search

Biomedical subjects

B Glück

Publications and source records attributed to B Glück.

At least 19 recordsLinked to original sources
PubMed2006

Validation of biocides against duck hepatitis B virus as a surrogate virus for human hepatitis B virus.

The use of a surrogate virus, namely duck hepatitis B virus (DHBV), has been recommended for testing the virucidal activity of chemical biocides against hepatitis B virus. To date, however, this model has not been recognized as a standard test in European countries, as its laboratory use is associated with considerable difficulties. As previous studies have demonstrated, several alternative procedures may improve the validation of DHBV infection in a cell culture system. Using indirect immunofluorescent antigen staining and the light cycler real-time polymerase chain reaction (PCR) technique, the virucidal activity of peracetic acid (PAA), povidone-iodine (PVP-I) and formaldehyde was tested against DHBV obtained from congenitally infected ducks or prepared from the transfected hepatoma D2 cell line. The results demonstrated that inactivation of DHBV from the D2 cell line was achieved with lower concentrations of the biocides and within shorter exposure time intervals. These lower concentration-exposure time values for DHBV from D2 cells in comparison with DHBV from infected ducks indicated a higher sensitivity of the virus derived from D2 cells. In addition, concentrations of PAA and PVP-I that significantly inactivated DHBV in suspension tests were not able to destroy the viral genome. In conclusion, DHBV from congenitally infected ducks should be used for virucidal testing of chemical biocides against DHBV; DHBV prepared from D2 cells is unsuitable due to its higher sensitivity to biocides. Indirect immunofluorescent staining allows reliable detection of DHBV infectivity, whereas the hepadnavirucidal effect can be evaluated by quantitative PCR.

Animals↗
PubMed2004

Electroporation of cell membranes supporting penetration of photodynamic active macromolecular chromophore dextrans.

The aim is to demonstrate that macromolecular chromophore dextrans (Cibacron-dextran) acting as photosensitizers can be transported easily into cancer cells by electroporation of their membranes (short electric pulses on cell suspension between electrodes). There are two possibilities, either:(A)irradiation starts with the electropulse-showed with easily penetrating thiopyronin-yielding nearly 100% dead cells;(B)irradiation starts after a resealing time of membrane pores during which macromolecular photosensitizers can penetrate into cells. In this way, fractions of Cibacron-dextran with molecular weights (Mw) 3300, 10,900 and 500,000 are now able to kill. This combination of bioelectrochemistry and photobiology will be suitable also for other biopolymers, connected with photodynamic active chromophores (e.g. chromopeptides) to transport them through cell walls and membranes into cells and tissues. The human cancer cells U-935 and K-562 (pulsed by 1.15 kV/cm field strength) additionally or synergistically reach high rates of necrotic cells (colored by trypan blue) by this combination.

Cell Line, Tumor↗
PubMed2001

Persistent expression of cytokines in the chronic stage of CVB3-induced myocarditis in NMRI mice.

Coxsackievirus B3 (CVB3)-induced myocarditis in NMRI mice represents a model for studying the pathogenesis of this chronic heart disease. Previously, we reported on specific cytokine patterns during the acute stage of myocarditis since cytokines are thought to play the important role in this cardiomyopathy. In this study, the expression of various cytokine mRNAs and CVB3-RNA kinetics was examined with particular emphasis on the late phase of myocarditis, by using reverse transcriptase-polymerase chain reaction (RT-PCR), in situ hybridization (ISH) and immunohistochemistry (IHC). In addition, replicating and persisting CVB3-RNAs were semiquantified by PCR-ELISA. Distinct histopathological changes responsible for ongoing heart disease were found and characterized by increased fibrosis, persistent cellular infiltration and degenerated necrotic myocytes. One of the most important findings of this study was that the mRNA-expression of TNF- alpha, IL-1 alpha, interferon- gamma, IL-10, IL-18, macrophage inflammatory protein-1 alpha (MIP-1 alpha), transforming growth factor- beta (TGF- beta) and inducible nitric oxide synthase (iNOS) persisted as long as 98 days after the virus infection. The induction of IL-10 as well as IFN- gamma mRNAs was also verified by ISH and IHC at days 28 and 98 p.i. The clearly apparent persistence of the viral genomes in the myocardium of infected mice was confirmed by seminested PCR, ISH, and PCR-enzyme linked immunoabsorbent assay (ELISA), showing the highest amount of viral RNA in myocardial cells at day 7 after infection. These data indicate that the persistence of viral RNA is associated with persistently high levels of cytokine mRNAs which, when translated, could severely contribute to pathological changes and injury of connective tissue in the chronic stage of myocarditis.

Animals↗
PubMed2001

Damaged myocytes as detected by the colocalization of DNA fragmentation and tissue transglutaminase and their prognostic significance in enterovirus-associated dilated cardiomyopathy.

BACKGROUND: Apoptotic cardiac myocytes have been described in chronic heart failure, but no data exist on the relationship between these 'damaged' myocytes and myocardial detection of enterovirus RNA often associated with dilated cardiomyopathy (DCM). DESIGN: In patients with idiopathic DCM, endomyocardial biopsy samples were studied for enteroviral RNA by one step reverse transcription-polymerase chain reaction (PCR) and a subsequent hybridization of the PCR product using a Southern blot technique. The endomyocardial biopsies were further investigated for markers of cell damage and apoptosis: DNA fragmentation and expression of tissue-transglutaminase (TTG) in the myocytes using the in-situ endlabelling method or an anti-TTG-staining, respectively. To assess the prognostic significance of these two markers the correlation between the percentage of myocytes positive both for DNA fragmentation and TTG (the index of damaged myocytes) and the hemodynamic course of the patients during a mean follow-up period of 15.9 +/- 6.2 months was investigated prospectively by echocardiography. RESULTS: In 14 (45%) of the 31 patients with idiopathic DCM, enteroviral RNA was found in the endomyocardial biopsy samples, while 17 patients (55%) were enterovirus-negative. In enterovirus-positive patients, the index of 'damaged' myocytes was significantly lower (10.7 +/- 4.9% vs. 19.2 +/- 8.8%, P = 0.002) and the left ventricular ejection fraction (LVEF) improved significantly (P = 0.00017 vs. P = 0.13) during long-term follow-up. In addition, a weak negative correlation was seen between the index of damaged myocytes and the changes in LVEF in all patients during long-term follow-up (r = - 0.48, P = 0.004). CONCLUSION: Our results favour the view that enterovirus-positive patients with DCM have less damaged myocytes and a better haemodynamic course than enterovirus-negative patients.

Adult↗
PubMed2001

Inhibition of proliferation of human lymphoma cells U937 by a 50 Hz electromagnetic field.

Weak pulsating electromagnetically induced fields (PEMF) by Helmholtz coils changes cell metabolism, if cells are treated with a certain range of frequency and amplitude. The influence on proliferation of human histiocytic lymphoma cells U937 has been studied applying a sinusoidal 50 Hz field with amplitudes of the flux density B = 0.3 to 4.7 mT for 4 days. No difference between experiment and control was found in the region 0.3 and 2 mT. However, stronger fields (> or =2.5 mT) inhibit cell division. Fields > or =3.5 mT treatment kill > or =80% of the cell number at the beginning (1.5 x 10(5)/ml). This effect may be an electromagnetocally induced cell death as the first step for a non-invasive application on cell proliferation process.

Apoptosis↗
PubMed2000

Expression of inducible nitric oxide synthase in experimental viral myocarditis.

Nitric oxide (NO) is an important bioactive molecule with regulatory, cytotoxic or cytoprotective properties. In virus-induced myocarditis, NO mediates host defense mechanisms against the infection or causes cardiac dysfunctions. NO is synthesized from L-arginine by the enzyme nitric oxide synthase (NOS). The expression of the inducible form of the nitric oxide synthase (iNOS) is regulated by cytokines, involved in the complex myocardial immune response to enterovirus infections. The present study was undertaken to characterize the role of iNOS and NO in the murine model of viral myocarditis induced by coxsackievirus B3 (CVB3). In response to CVB3 infection we investigated the time course of iNOS induction in correlation with cytokine mRNA expression (TNF-alpha, IL-1 alpha, IFN-gamma, TGF-beta) in the heart of NMRI mice by RT-PCR. Positive PCR signals for viral RNA were found in the acute and chronic stage of disease by seminested PCR, indicating the persistence of viral genome. We found distinct expression of iNOS at all time points (1, 2, 3, 4, 7, 14, 28, 56, 98 days post infection [p.i.]). Higher iNOS mRNA levels were identified between days 4 until 28 p.i. in comparison to day 56 and 98 p.i. using densitometric values. The mRNA of the inflammatory cytokines TNF-alpha, IL-1 alpha, IFN-gamma appeared at days 1, 4, and 7 p.i., peaked at day 7 p.i. and persisted until day 98 p.i. Similar like the iNOS mRNA pattern was the expression profile of TGF-beta. Using in situ hybridization and immunohistochemistry iNOS was localized in infiltrates, vascular endothelial cells, smooth muscle cells, myocytes and throughout the interstitial spaces between myocardial fibers in the heart sections of NMRI mice. Increased levels of NO were measured as total nitrate/nitrite concentration in the sera of mice from day 7 until day 28 p.i.

Animals↗
PubMed2000

Congenital skin lesions caused by intrauterine infection with coxsackievirus B3.

BACKGROUND: Serious neonatal coxsackievirus infections transplacentally acquired in late pregnancy involve primarily the central nervous system, heart, liver and rarely the skin. PATIENTS AND METHODS: A boy born with a disseminated papulovesicular, nodular, bullous and necrotic ulcerated rash at 39 weeks gestational age developed pneumonia, carditis and hepatitis during the first days after birth. Molecular biological and serological methods were used for virological diagnosis. RESULTS: Coxsackievirus B3 (CVB3) was found in throat swabs and/or feces of the neonate and his mother. In addition, there was serological evidence of intrauterine infection. CONCLUSION: Intrauterine transmission of CVB3 during late pregnancy may lead to varicella-like congenital skin lesions.

Adult↗
PubMed2000

Cytokine profiles in heart, spleen, and thymus during the acute stage of experimental coxsackievirus B3-induced chronic myocarditis.

Since cytokines play an important role in the pathogenesis of virus-induced chronic heart diseases, cytokine mRNA expression was studied in coxsackievirus B3-infected NMRI mice during the acute phase of myocarditis until the onset of chronic cardiac disease. Virus replication, cytokine induction, inflammatory cell infiltration and myocardial damage were studied by titer determination, reverse transcription-polymerase chain reaction (RT-PCR), and histopathology. To investigate whether the coxsackievirus B3-induced cytokine mRNA accumulation was only limited to the heart or generalized, spleen and thymus specimens were also included. Surprisingly, interleukin (IL)-10 as a deactivator of T cell and macrophage functions was transcribed in the myocardium nearly in parallel with virus replication from Day 1 through Day 14. At Day 3 p.i., the mRNA of IL-1alpha, tumor necrosis factor (TNF)-alpha, IL-6, and interferon (IFN)-beta accumulated. At Days 4, 7, and 14, IL-12-specific mRNA was produced. Furthermore, increasing amounts of IFN-gamma mRNA were found, whereas IL-2 and IL-4 mRNA remained undetectable. TNF-alpha, IL-1alpha, IL-10, IL-12, and IFN-gamma mRNA persisted into the late stage of myocarditis. In the spleen a closely correlated expression of virus and IL-10-specific mRNAs was also found, and in addition, IFN-beta, TNF-alpha, and IL-6 were detected. In striking contrast to heart and spleen tissue, the distinct expression of viral RNA in the thymus was not accompanied by an increased cytokine mRNA production. These data provide evidence for a unique coxsackievirus B3-induced cytokine pattern in the myocardium and spleen and suggest that persistently expressed IL-10 may play a leading role in acute and chronic myocarditis by subverting the immune response.

Acute Disease↗
PubMed1999

Effects of propofol (intravenous propofol emulsion) on cell membranes measured by electrofusion and electroporation.

The influence of propofol (CAS 2078-54-8 (intravenous propofol emulsion) on cell membrane properties was investigated in vitro with techniques of cell electrofusion and cell electroporation. Human lymphoma cells and plant protoplasts were chosen as a model system. Propofol (intravenous propofol emulsion) decreased the electrofusion yield of the cells and their membrane permeability. A 50% decrease in relative electrofusion was observed in human lymphoma cells in the presence of about 0.05 mmol/l propofol (intravenous propofol emulsion) and in plant protoplasts in the presence of about 0.1 mmol/l. The fusion of human lymphoma cells was inhibited to 100% at concentrations higher than 0.2 mmol/l propofol and 0.4 mmol/l intravenous propofol emulsion. The membrane permeability of human lymphoma cells decreased by the factor of two with increasing propofol concentrations up to about 0.1 mmol/l. The effects of electroporation were highly reversible. Propofol (intravenous propofol emulsion) was more effective than tetracaine. These sensitive techniques are suitable for the investigation of interactions between anesthetic drugs and the cell membrane.

Anesthetics, Intravenous↗
PubMed1989

[Interferon induction under in vitro conditions].

The procedures generally used for the in vitro induction of interferon exploit fibroblast or leucocyte culture suspensions. Several factors and conditions influencing the capacity for IFN induction were studied, with the following results. In contrast to previous findings, optimum IFN induction was obtained at 37 degrees C, rather than 30 degrees C, when human fibroblasts were induced with 100 micrograms/ml of Poly (IC). There was a direct correlation between the dose of the inducing agent applied and the amount of IFN produced. Also, the cells were excellently super-inducible with metabolic inhibitors like actinomycin D and cycloheximine. In addition, priming procedures enhanced IFN induction in human fibroblasts. Comparing different cell types with respect to their ability to be induced for IFN production, we found that different cell types show great differences in their inducer sensitivity. Finally, the response of different cell culture systems was highly variable when induced with different compounds.

Cells, Cultured↗
PubMed1989

[Sensitivity of different cell lines to interferons: the relative antiviral activity as a function of the interferon subtype].

The phenomenon that rHuIFN-alpha1(D) displays an apparently higher antiviral activity when assayed on bovine cells as compared to human cell lines was applied to the elucidation of the nature of recombinant HuIFN prepared in our institute. These investigations were carried out by using a microtitre test, which defines biological activity as the IFN concentration leading to 50% inhibition of the cytopathic effect of vesicular stomatitis virus (VSV). In addition, the ability of IFN to diminish the reproduction of infectious viruses was monitored. The two methods yielded similar results. With bovine cells, antiviral activities of the same order of magnitude were observed, regardless of the interferon types applied, i.e. rHuIFN-alpha 1, rHuIFN-alpha 2 and human leukocyte interferon. On human fibroblasts, however, rHuIFN-alpha 1 had an apparently 45 to 165 times lower activity than the other two interferons. On human WISH cells, the differences in apparent activity between the respective IFNs were even greater, with factors of up to 212 fold being observed. Still more distinctive were the effects on murine L 929 cells where an antiviral effect could be confirmed only for rHuIFN-alpha 1 whereas the other two interferons proved completely inactive.

Animals↗
PubMed1989

[Studies using different human cell-culture systems for demonstrating interferon induction under in vitro conditions].

Five human cell culture systems (FL-cells, suspensions of tonsillar cells, FL-cells and suspensions of tonsillar cells combined, human fibroblasts, leukocyte suspensions) were tested with the international standard inducer Poly (IC) for the estimation of an in vitro induction of interferon under in vitro conditions. All induced cell systems have produced IFN. It can be concluded that alone the cell culture system represented by fibroblasts and leukocytes allow a reliable prediction concerning the induction of interferon under in vitro conditions.

Amnion↗
PubMed1988

AsnI: a novel class II restriction endonuclease from Arthrobacter sp., strain N-CM, recognizing 5'-AT/TAAT-3'.

A new class II restriction endonuclease, AsnI, with a novel sequence specificity was isolated from the Gram-positive eubacterium Arthrobacter species, strain N-CM. AsnI recognizes the unambiguously defined palindromic hexanucleotide (Formula: see text) consisting of A- and T-residues. The novel enzyme in the presence of Mg2+ cleaves specifically both strands as indicated by the arrows. The staggered cuts generate 5'-protruding ends with single-stranded 5'-TA-3' dinucleotide extensions. The novel enzyme may be a useful tool for cloning experiments by complementation of the few enzymes such as PstI and PvuI cutting only once in the Ampr-gene of plasmids pBR322 and pBR328.

Arthrobacter↗
PubMed1988

[Experimental studies of in vitro IFN induction by different polynucleotides in human cell culture systems].

Several polynucleotides were tested for interferon induction in comparison with the standard Poly (IC) in human diploid fibroblasts and in human leukocyte suspensions. We received high IFN-titre following superinduction of the polynucleotides in human fibroblasts. These results show that under superinduction conditions partly 3 times more interferon is induced in comparison with the standard inductor Poly (IC). The tested concentration of 10 micrograms/ml polynucleotides did not result in any IFN yields or only in very low ones in human leukocytes, which were only within the range of detectability.

Cells, Cultured↗
PubMed1986

[Interferon sensitivity of various cell lines].

An economic assay to determine the yield of interferon is necessary for the induction, production and purification of interferon. Using the inhibition of cytopathic effect of vesicular stomatitis virus in a microtitre system, we compared the susceptibility of different cell lines against an internal IFN alpha standard obtained from Sendai virus-induced human leukocytes. Human fibroblasts carrying trisomy G 21 and bovine MDBK cells showed the highest sensitivity followed by normal human fibroblasts. Human RH kidney cells exhibited a susceptibility similar to that of human WISH amnion cells frequently used by others. The human amnion cell line FL and monkey Vero kidney cells, as described here, were unsuitable for the determination of IFN yields.

Animals↗
PubMed1977

[The use of primate tissue homogenates for quality control in the creatine kinase-MB determination with inhibiting antibodies (author's transl)].

The creatine kinase isoenzymes CK-MM, CK-MB and CK-BB from Rhesus monkey heart and brain tissue homogenates were separated chromatographically. Thereafter it could be demonstrated that the activity of the simian subunit CK-M is completely inhibited by anti-inhibitory-CK-M serum. Thus control sera from simian tissue are in principle suited for quality control in an immunological determination of creatine kinase-MB. The intra-assay variance and interassay variance were n = 56, -/x = 29.2 U/1, SD = 3.2 U/1, CV = 11.1% and n= 12, -/x = 166.7 U/1, SD = 5.0 U/1, CV = 3.0% respectively. It is desirable to develop control sera with catalytic concentrations of creatine kinase-MB in a lower range.

Animals↗