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Biomedical subjects

H Struy

Publications and source records attributed to H Struy.

At least 19 recordsLinked to original sources
PubMed2000

Protection of mitochondrial integrity from oxidative stress by the triaminopyridine derivative flupirtine.

The suitability of the triaminopyridine derivative flupirtine, an analgesic drug with antioxidative property [Gassen, M., Pergande, G. and Youdim, M.B.H. (1998) Biochem. Pharmacol. 56, 1323-1329], for the preservation of mitochondrial integrity from oxidative stress-induced damage was studied. Rat liver mitochondria were exposed to strong oxidative stress as generated by Fe(2+) plus ascorbate. Peroxidation damage of membrane lipids was followed by the measurement of thiobarbituric acid reactive substances. Protein oxidation was estimated by electron spin resonance spectroscopy, after labeling of the 'peroxidized' mitochondria with 4-maleimido-2, 2,6,6-tetramethylpiperidine-1-oxyl. We found that (i) low concentrations of flupirtine (10 microM) protect lipids and also proteins (with lesser efficiency) from attacks of reactive oxygen species; (ii) flupirtine remarkably delayed the decline of complex mitochondrial functions, such as the respiratory control or the Ca(2+) retention capacity of mitochondria, under oxidative stress; and (iii) the ADP/ATP antiporter (ANT), a main component of the oxidative phosphorylation machinery as well as a core component of the permeability transition pore complex, seems to be a membrane protein particularly protected by flupirtine. In conclusion, the preservation of the Ca(2+) buffer capacity of mitochondria and of the ANT activity against oxidative stress supports an antiapoptotic application of flupirtine.

Aminopyridines↗
PubMed2000

Effect of granulocyte colony-stimulating factor treatment on ex vivo neutrophil functions in nonneutropenic surgical intensive care patients.

Granulocyte colony-stimulating factor (G-CSF) preferentially stimulates growth and differentiation of neutrophil precursors and activates neutrophil functions. The aim of the present study was to investigate the functional response of the neutrophil to exogenous recombinant human G-CSF (rHuG-CSF) in nonneutropenic patients. In 30 surgical intensive care unit patients with severely impaired wound healing, leukocyte differential count, plasma G-CSF level, and a broad spectrum of neutrophil functions were monitored before (day 0), throughout (days 1 and 5), and at days 1 and 5 after stopping G-CSF treatment. G-CSF application resulted in a 3.5-fold increase in peripheral blood granulocyte count at day 5 of treatment. The mean plasma G-CSF level rose from 48 to a maximum of 2314 pg/ml at day 1 of G-CSF therapy. Neutrophil chemotaxis and stimulated lysozyme release were decreased throughout G-CSF treatment, whereas respiratory burst activity, phagocytic activity, and intracellular calcium concentration were enhanced by G-CSF. Neutrophil membrane depolarization remained unaffected. The increased count and activation state of neutrophils were associated with clinical improvement in most of these patients. Thus, G-CSF may be a useful adjuvant treatment for nonneutropenic patients with severely impaired wound healing.

Adult↗
PubMed2000

Investigation of annexin V binding to lymphocytes after extracorporeal photoimmunotherapy as an early marker of apoptosis.

BACKGROUND: Induction of programmed cell death is assumed to be a possible effect of extracorporeal photoimmunotherapy (ECPI). OBJECTIVE: In the present study lymphocytes of patients with cutaneous T cell lymphoma undergoing ECPI were investigated for early apoptotic events. METHODS: Annexin V, known for its selective affinity to phospholipids, was used to detect early phases of apoptosis. Simultaneous staining with propidium iodide binding to DNA allowed detection of late apoptotic/necrotic cells. RESULTS: At 1 h after ECPI, an increase in early apoptotic cells was found indicating a direct effect of ECPI. At 20 h after each ECPI session, a delayed increase in the number of apoptotic lymphocytes was observed in early apoptotic annexin-stained cells and in late apoptotic cells, whereas in nonirradiated cells no remarkable changes were found. Apoptosis was confirmed by altered light scattering properties and DNA fragmentation. CONCLUSION: The apoptotic cell death of reinfused lymphocytes is supposed to be a therapeutic effect of ECPI.

Aged↗
PubMed1999

Refsum disease diagnostic marker phytanic acid alters the physical state of membrane proteins of liver mitochondria.

Phytanic acid (3,7,11,15-tetramethylhexadecanoic acid), a branched chain fatty acid accumulating in Refsum disease to high levels throughout the body, induces uncoupling of rat liver mitochondria similar to non-branched fatty acids (e.g. palmitic acid), but the contribution of the ADP/ATP carrier or the aspartate/glutamate carrier in phytanic acid-induced uncoupling is of minor importance. Possible deleterious effects of phytanic acid on membrane-linked energy coupling processes were studied by ESR spectroscopy using rat liver mitochondria and a membrane preparation labeled with the lipid-specific spin probe 5-doxylstearic acid (5-DSA) or the protein-specific spin probe MAL-TEMPO (4-maleimido-2,2,6, 6-tetramethyl-piperidine-1-oxyl). The effects of phytanic acid on phospholipid molecular dynamics and on the physical state of membrane proteins were quantified by estimation of the order parameter or the ratio of the amplitudes of the weakly to strongly immobilized MAL-TEMPO binding sites (W/S ratio), respectively. It was found, that phytanic acid (1) increased the mobility of phospholipid molecules (indicated by a decrease in the order parameter) and (2) altered the conformational state and/or the segmental mobility of membrane proteins (indicated by a drastic decrease in the W/S ratio). Unsaturated fatty acids with multiple cis-double bonds (e.g. linolenic or arachidonic acid), but not non-branched FFA (ranging from chain length C10:0 to C18:0), also decrease the W/S ratio. It is hypothesized that the interaction of phytanic acid with transmembrane proteins might stimulate the proton permeability through the mitochondrial inner membrane according to a mechanism, different to a protein-supported fatty acid cycling.

Biological Transport↗
PubMed1997

Effects of retinoids on the generation of neutrophil-derived reactive oxygen species studied by EPR spin trapping techniques.

OBJECTIVE: To study the potential efficacy of retinoids on granulocytes with regard to their role in inflammatory dermatoses. METHODS: We investigated the in vitro effect of acitretin and isotretinoin on the generation of reactive oxygen species (ROS) by stimulated human neutrophils using EPR spin trapping techniques. RESULTS: The effects of the two retinoids on ROS generation by neutrophils were different. Acitretin increased the generation of hydroxyl radicals, whereas isotretinoin showed an antioxidant activity against the superoxide anion. CONCLUSIONS: Our study demonstrates retinoid type-dependent effects on ROS production by stimulated neutrophils.

Acitretin↗
PubMed1997

Protection against UVA damage and effects on neutrophil-derived reactive oxygen species by beta-carotene.

OBJECTIVE: Phagocyte-derived reactive oxygen species (ROS) are involved in microbicidal activities as well as in tissue damage at sites of inflammation. Carotenoids play an important function in protecting cells from oxidant damage. We investigated the in vitro and in vivo effect of 13-cis and 9-cis-beta-carotene on human neutrophils. METHODS: Neutrophils from healthy donors in the presence of 0.25 mumol/L-1 mumol/l beta-carotene and from subjects under beta-carotene supplementation and UVA or UVA/B exposure were stimulated by opsonized zymosan and the generation of ROS was measured by electron spin resonance spectroscopy. RESULTS: Our in vitro results show different effects of the two isomers on stimulated neutrophils. 9-cis-beta-carotene did not produce any change, whereas 13-cis-beta-carotene significantly and concentration-dependent inhibited the ROS generation by stimulated neutrophils. Further, in a controlled study, we were able to demonstrate an in vivo protective effect of beta-carotene on neutrophils against UVA damage by beta-carotene supplemented subjects.

Electron Spin Resonance Spectroscopy↗
PubMed1997

Further search for virulence factors encoded by Salmonella serovar-specific plasmids.

The so called Salmonella virulence plasmids which are specifically prevalent among some of the S. enterica serovars were shown to contribute only marginally to the virulence make-up of salmonella, which is in contrast to Shigella and Yersinia spp. The experiments reported in this paper failed to find encoded plasmid factors which contribute to serum resistance, surface antigens, immunoinsufficiency or to up-regulation of chromosomally encoded factors such as toxins, surface antigens etc. Taking into consideration the rare prevalence of these plasmids among S. enterica but their common occurrence among a few of its serovars, their virulence implication remains an enigma.

Animals↗
PubMed1997

[Cellular and humoral functions in acute pancreatitis].

Infectious complications are the leading cause of death in acute pancreatitis. Individual factors of immune defence could be of significance, whether or not a patient develops a severe course with infectious complications. In a prospective 5-year trial including 72 patients, we investigated 29 cellular and humoral markers of the body's defence system for their potential to indicate the severity and course of acute pancreatitis. Complement factors C3 and C4 as well as immunoglobulins IgG, IgM and IgA were normal, in general. Measurable levels of IL-1 alpha, IL-1 beta, IL-2 and sIL-2R could be detected only occasionally. Values of alpha 1-AT, TNF-alpha, TNF alpha-Rp75, neopterin, sICAM-1, IL-8, IL-1RA and sIL-6R did not correlate with a severe course. Due to the high magnitude of increase, CRP, IL-6 and granulocyte elastase were the best indicators of the inflammatory process. Delayed-type hypersensitivity response was the only early predictor of a severe course. It was superior over other cellular markers such as monocyte count or CD4+/CD8+ ratio. In vitro function of polymorphonuclear granulocytes (PMN) was not adequate to the severity of the disease already during the first week of illness. During further course, PMN motility and capacities to produce reactive oxygen species even worsened. The compromized PMN function could explain the frequent development of infectious complications in patients suffering from severe pancreatitis. These results should encourage new concepts of infection prophylaxis using stimulants of cellular defence.

Acute Disease↗
PubMed1991

[Determination of thyroglobulin autoantibodies using enzyme immunoassay, radioimmunoassay and passive hemagglutination].

A solid-phase enzyme immunoassay, a radioimmunoassay and the passive hemagglutination were tested for the determination of antithyroglobulin autoantibodies. The antibody-titres detected with these methods showed a good correlation. The sensitivities of the solid-phase immunoassays are four times higher than the sensitivity of the passive hemagglutination. For the diagnosis of thyroid autoimmune diseases the enzyme immunoassay.

Autoantibodies↗
PubMed1989

[Systemic effects of ultraviolet, visible and infrared radiation in serial whole body irradiation. I. Oxygen utilization, flow properties of blood, hemodynamics, blood components and phagocytosis].

31 healthy volunteers at the age of 19 to 29 years underwent whole-body irradiations by either ultraviolet radiation (NARVA UVS 65-2; continuous sunshine-like emission, predominantly UVA plus 8% UVB; cumulative doses after 4 and 20 irradiations 8.8 J/cm2 and 51.0 J/cm2, respectively), or visible light (emission of a 3,500 Watt lamp HGMI 3500 DL, Tungsram CSSR, filtered through 6 mm window glass; cumulative dose 267.0 J/cm2 after 4 irradiations) or infrared radiation (250 Watt infrared lamps NARVA "Biotherm", emitting more than 70% infrared radiation; cumulative dose 159.0 J/cm2 after 4 irradiations). Before, during and after the irradiation series the following investigations were made: Arterial and venous oxygen pressure, oxygen utilization index; flow properties of peripheral blood (plasma viscosity, erythrocyte aggregation kinetics, apparent blood viscosity); hemodynamics (veineal plethysmography, 133Xenon clearance, functional diameter of small blood vessels, peripheral blood pressure), phagocytotic capacity of polymorphonuclear white blood cells; hematological parameters (blood sedimentation rate, polymorphonuclear and eosinophilic blood cells, red blood cells, hemoglobin, hematocrit), serum proteins (IgG, IgA, IgM, complement C3, alpha-1-glycoprotein, alpha-1-antitrypsin, haptoglobin, transferrin); calcium and phosphate in serum. As far as irradiance, dose and treatment frequencies are concerned, the experimental conditions were very similar to those in phototherapeutical practice. Under these circumstances there were no hints for unwanted early effects after application of all the three kinds of optical radiation used in that study. Considerable systemic responses exclusively were found by use of ultraviolet radiation. Under these experimental conditions according to dermatological phototherapy it has been proven the following biopositive systemic responses are due to happen: increase of serum calcium and phosphate, improvement of blood oxygen utilization, improvement of blood flow properties, and enhanced phagocytic capacity of polymorphonuclear white blood cells. Regarding the parameters taken in that study, no early unwanted side effects are to expect after therapeutical application of rather large doses of visible light or infrared radiation.

Adult↗
PubMed1989

[Axial filament antigen enzyme immunoassay (AF-ELISA) in syphilis serology].

179 sera from patients with various stages of syphilis were investigated in the axial filament enzyme linked immunosorbent assay (AF-ELISA), the Treponema pallidum haemagglutination assay (TPHA), the fluorescence treponemal antibody absorption (FTA-ABS) test and the cardiolipin micro precipitation test (CMT). For the control of specificity 30 problem sera from non Treponema pallidum infected patients with a high quantity of Treponema genus specific antibodies and 40 sera from people without syphilis were also investigated. The sensitivity of the AF-ELISA (98.3%) was comparable with the TPHA (99.4%) and the FTA-ABS-test (98.9%). It was a high unspecificity in the group of problem sera.

Antigens, Bacterial↗
PubMed1989

[Characterization of treponemal axial filament antigens using the Western blot].

Analysis by SDS-PAGE of axial filaments of cultivable treponemes showed 3 major bands: a 33/34 kD doublet and a 37 kD polypeptide. In sera from patients with various stages of syphilis, from biological false positive reactors, and from negative controls the most consistent reaction was detected against the doublet, but only sera from patients with primary or secondary syphilis reacted with the 37 kD axial filament polypeptides. About 6 weeks after antibiotic treatment sera had lost their reactivity with 37 kD antigens in agreement with decreasing antibodies in VDRL-test. Because of their recognition early in infection 37 kD-proteins are postulated to use in serodiagnostic assays, but our data emphasize also the need for use further antigens in tests for diagnosis in later stages of syphilis.

Antigens, Bacterial↗
PubMed1988

[Determination of immune complexes in the serum of pregnant patients and puerperal females with EPH gestosis].

We analyzed the blood sera from 100 patients with EPH gestosis and from 50 women with normal pregnancy to explore the immunological reactions during gestosis. The sera of cord blood were included in the investigations. We determined the circulating immune complexes by conglutinin and C1q solid phase radioimmunoassay and by polyethyleneglycol precipitation. It has been established by conglutinin RIA that during pregnancy the women with gestosis have significant higher concentrations of immune complexes than the control group. During puerperium and in the cord blood the values are significantly lower than during pregnancy in both groups. The estimations of immune complexes by C1q RIA have shown that the differences between the two groups are insignificant and the lowest values are in the cord blood. The concentrations of immune complexes estimated by PEG precipitation were not significantly different between the two groups. It is concluded that immune complexes are in connection with the pathogenesis of preeclampsia.

Adult↗
PubMed1988

Alterations in calmodulin content of rat brain areas after chronic application of haloperidol and amphetamine.

The water-soluble (cytosolic) and Lubrol-soluble (membrane-bound) calmodulin contents were determined radioimmunologically in fractions of striatum, hippocampus and cerebellum of dopamine supersensitive rats. Development of supersensitivity was the sequel of 3-weeks treatment of the animals with 1 mg/kg haloperidol or 5 mg/kg amphetamine i.p. daily. In the dopamine-rich striatum, the membrane-bound calmodulin content was increased by both modes of treatment, consistent with data from the literature. The patterns suggest that additional calmodulin was synthesized under the conditions studied. The hippocampus, the region poor in dopamine while playing an essential role in learning and memory formation processes, revealed similar patterns after both modes of treatment. However, in this region a pronounced translocation was seen, i.e. a redistribution from the cytosolic into the membrane compartment, without signs evidencing enhanced synthesis. The third region under investigation, the cerebellum, did not show any alterations in calmodulin content. Differentiation between pre- and postsynaptic changes was not possible. The results are discussed in the light of the present knowledge about participation of dopaminergic systems in processes of neuronal plasticity.

Amphetamine↗
PubMed1987

[Detection and differentiation of autoantibodies to extractable nuclear antigens with immunoenzyme tests].

Nuclear antigens were extracted from calf thymus with phosphate-buffered saline The 60-80% ammonium sulfate fraction (ASF) of thymus extract contained SS-B-, the 30-60% ASF Sm- and U1-RNP-, and the chromatographically purified 30-60% ASF only Sm antigen. With these fractions enzyme immunoassays were developed for quantitative determination of Sm-, U1-RNP-, and SS-B autoantibodies. Out of 144 sera with antinuclear antibodies 85% were positive in the enzyme immunoassays, 41% in immunofluorescence tests on liver sections (12% speckled, 29% homogeneous immunofluorescence pattern), and 10% in Ouchterlony tests. 26% of the sera were positive in enzyme immunoassays and immunofluorescence tests. All antibody specificities detected by immunodiffusion could be confirmed by enzyme immunoassay. The enzyme immunoassay is far more sensitive then immunodiffusion and in contrast to immunofluorescence allows antibody specificities to be determined. Enzyme immunoassays are recommended for the diagnosis of rheumatic diseases.

Antibodies, Antinuclear↗
PubMed1987

[Detection of circulating immune complexes in patients with EPH gestosis or intrauterine fetal growth retardation].

Sera from 19 patients with EPH gestosis, 22 patients with hypotrophic newborns, and a control group of ten women with normal pregnancy and fetuses were studied for the presence of circulating immune complexes. Both the C1q solid-phase radioimmunoassay and the polyethylene glycol precipitation test revealed significantly higher levels of circulating immune complexes in both groups of patients.

Antigen-Antibody Complex↗