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  • 1
    ISSN: 1432-0428
    Keywords: Keywords Advanced glycation endproducts ; plasminogen activator inhibitor-1 ; endothelial cells ; microangiopathy ; thrombogenesis.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Several thrombogenic abnormalities are associated with diabetes. To investigate the underlying molecular mechanisms, we examined the effects of advanced glycation endproducts (AGE), non-enzymatically glycated protein derivatives, on the production of prostacyclin (PGI2), an anti-thrombogenic prostanoid, and of plasminogen activator inhibitor-1 (PAI-1), a fast-acting serine protease inhibitor of fibrinolysis, in human microvascular endothelial cells (EC). Firstly, AGE-bovine serum albumin (BSA) but not non-glycated BSA, was found to considerably decrease the production of PGI2 to about two-thirds of the control value. Secondly, quantitative reverse transcription-polymerase chain reaction showed that AGE-BSA increased the EC levels of mRNA coding for PAI-1, this being associated with a concomitant increase in the immunoreactive PAI-1 contents and the anti-fibrinolytic activity. Thirdly, the effects of AGE on PGI2 and PAI-1 syntheses in EC were found to be mediated by a receptor for AGE (RAGE) because antisense DNA against RAGE mRNA could reverse the AGE effects. Further, it was found that AGE decreased the intracellular cyclic AMP concentrations in EC and that cyclic AMP agonists such as dibutyryl cyclic AMP, forskolin and PGI2 analogue reduced the AGE-stimulated PAI-1 production, suggesting the involvement of cyclic AMP in the AGE-signalling pathway. The results thus suggest that AGE have the ability to cause platelet aggregation and fibrin stabilization, resulting in a predisposition to thrombogenesis and thereby contributing to the development and progression of diabetic vascular complications. [Diabetologia (1998) 41: 1435–1441]
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 64 (1997), S. 419-422 
    ISSN: 1432-0630
    Keywords: PACS: 68.35
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: , and subsequently deposited onto the surface by the application of -8.5 V 300 ms pulses to the sample. The physical mechanisms involved are hydrogen diffusion on the tip via field-gradient-induced diffusion and hydrogen deposition due to electronic excitation.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 112 (1996), S. 112-118 
    ISSN: 1432-1106
    Keywords: Monosynaptic reflex ; H-reflex variability ; Fractal ; Supraspinal ; Spinal cord injury ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In our previous study, $${1 \mathord{\left/ {\vphantom {1 {f^\beta }}} \right. \kern-\nulldelimiterspace} {f^\beta }}$$ -type power spectrum with the spectral exponent β significantly greater than zero was found in the variability of soleus H-reflex amplitudes. This result indicated that the H-reflex variability was time-correlated owing to fractal characteristics. Furthermore, it was also suggested that the fractal characteristics were generated at the spinal level. The purpose of the present study was to investigate whether the fractal nature of the H-reflex variability was influenced by the loss of supraspinal input. Six healthy normal subjects and seven patients with spinal cord injury participated in this study. Soleus H-reflexes were evoked every l s from both legs simultaneously (stimulation intensity: motor threshold) and 1050 successive amplitudes of the H-reflex were recorded. The H-reflex sequence evoked from each leg was analyzed by “coarse graining spectral analysis” to calculate the spectral exponent β. The value of β was used to evaluate the level of time-correlation (fractal correlation). Cross-spectral analysis was used to evaluate the degree of synchronization between the H-reflex sequences evoked from both legs. The β values for normal subjects (0.84±0.33, left leg; 0.88±0.34, right leg) were significantly greater (P〈0.001) than those for patients (0.31±0.18, left leg; 0.32±0.14, right leg), suggesting that the H-reflex sequences for normal subjects were more time-correlated than for patients. In the frequency range less than 0.2 Hz, the coherence of both legs was high (0.41±0.14) for normal subjects as compared to 0.20±0.12 for patients (P〈0.005). In this frequency range, the phase was almost 0 rad for normal subjects, indicating that the H-reflex variabilities of both legs were synchronized. These results suggested that (1) the strong fractal correlation observed in the H-reflex sequences for normal subjects was associated with supraspinal input, and (2) such supraspinal input had equal influence on the reflex arcs of the soleus of both legs.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0942-0940
    Keywords: Stab wound ; autoradiography ; peripheral benzodiazepine receptor ; gliosis ; PK-11195
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Chronological studies of the development of the peripheral benzodiazepine receptor sites were undertaken with the goal of evaluating the sensitivity of this marker for the study of the gliosis development in the injured brain. No significant increase in [3H] PK-11195 binding occurred in the rat brain stab wound one day following the puncture. A significant increase in the receptor density (Bmax) from the second day onward was observed. The Bmax reached its highest levels in the grey matter on the sixth day after a 23-gauge needle wound (8.75 ± 0.09; pmol mg-tissue−1) and on the seventh day after an 18-gauge needle wound (8.98 ± 0.31 pmol mgtissue−1). In the white matter, the Bmaxwas greatest seven days after the wound (3.42 ± 0.07; pmol mg-tissue−1; 23-gauge needle and 3.56 ±0.1 pmol mg-tissue−1 in the 18-gauge needle injury). Between 30 and 60 days after the wound, the Bmax was significantly lower than the Bmax observed between 6 and 14 days. The Bmax in the wound produced with needles was seven to eight times greater than the Bmax in the grey matter of the ipsilateral and contralateral cortices. Histological examination showed that there were no astrocytes or macrophages in the stab wound one day after the lesion. However, the glial fibrillary acidic protein positive cells and macrophages appeared on D3 after an injury. Gliosis, as measured by the PK-11195 binding, was also observed in the remote contralateral cortex. Data shows that PK-11195 binding is a very sensitive method of evaluating brain injury and could be of great value in studying progressive injuries in the living human brain in conjunction with positron emission tomography.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0942-0940
    Keywords: Cerebral ischaemia ; local cerebral blood flow ; ischaemic damage ; PDBu binding activity ; duration of middle cerebral artery occlusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The alterations of the local cerebral blood flow (LCBF),3 H-phorbol 12,13-dibutyrate (PDBu) binding activity were measured, and histological findings were also examined during the closed time course (0, 1, 3, 5, 7 hour) after middle cerebral artery occlusion (MCAO) in rat brain to assess the complex pathophysiology of acute focal ischaemia. From 1 to 3 hours after the start of MCAO, significant (p 〈 0.01) hyperreactivity of the second messenger system involving PDBu binding may be present, despite low perfusion of LCBF, and severe damage in the striatum whereas sparing almost completely the cortex on histological examination. At 5 hours, the PDBu binding activity increased slightly but not significantly but is reduced markedly at 7 hours after MCAO compared with the control group. The measurement of PDBu binding activity, additionally to measuring the LCBF and observation of the histological change might be a useful indicator in determining the threshold and duration of ischaemia which cause functionally irreversible cell damage in the brain.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Il nuovo cimento della Società Italiana di Fisica 17 (1995), S. 1657-1662 
    ISSN: 0392-6737
    Keywords: Excitons and related phenomena (including electron-hole drops) ; Polaritons (including photon-phonon and photon-magnon interactions) ; Dynamics of nonlinear optical systems ; optical instabilities, optical chaos, and optical spatio-temporal dynamics ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary The linewidth of the microcavity exciton polariton is studied by onresonant and off-resonant photoluminescences. The two main contributions to the linewidth are caused by radiative loss and phonon scattering. The oscillator strength is found to be unmodified by the exciton-phonon coupling. Comparison is made between theory and experiment.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Oxford, UK : Chapman and Hall
    International journal of cosmetic science 20 (1998), S. 0 
    ISSN: 1468-2494
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: We present a new method to evaluate the photo-oxidative activity of sunscreening agents based on the photodynamic oxidation of uric acid. Uric acid was selected as the oxidant probe for its high reactivity to singlet oxygen and oxygen radicals, high sensitivity of detection using electrochemical (EC) techniques, low light absorptivity and high photochemical stability in the UVA/B region of interest, and stability to autoxidation. The method is demonstrated by the photodynamic oxidation of uric acid on co-irradiation with Rose Bengal, a highly efficient photosensitizing dye for the production of singlet oxygen (1O2). Using this assay we found that the relative photodynamic oxidation rates of UVB-absorbing sunscreens in 80% methanol on irradiation with 〉290 nm light decreased in the order 2-ethylhexyl 4-dimethylaminobenzoate (DMABA-2EH) ≫ 2-ethylhexyl 4-methoxycinnamate (MCA-2EH) and the experimental sunscreens, 1-(1,1-dimethylethyl)-3-octanoyl-4,4-dimethyl- 1,4,5,6,-tetrahydropyridine (ICI-319) and 1-(2-methylpropyl)-3-propionyl-4,4-dimethyl-1,4,5,6-tetrahydropyridine (ICI-855). The relative photodynamic oxidation rates of UVA-absorbing sunscreens decreased in the order 4-tert-butyl-4'-methoxydibenzoylmethane (BMDBM) and 4-(2-propyl)benzophenone (PB) 〉 2-hydroxy-4'-methoxy-benzophenone (HMB) and 2,2'-dihydroxy-4-methoxybenzophenone (DHMB). We have confirmed the photodynamic activity of DMABA-2EH for the production of singlet oxygen (1O2) using electron paramagnetic resonance (EPR) spectroscopy and the reagent 2,2,6,6-tetramethyl-4-piperidone (4-oxo-TEMP). We failed to detect the photodynamic production of the oxyradicals, superoxide (O2.-) and hydroxyl radical (HO.) using N-tert-butyl-a-phenylnitrone (PBN) and 5,5-dimethyl-1-pyrrolidine-1-oxide (DMPO) as a result of photochemical interference caused by these spin-trapping reagents. The uric acid photo-oxidation assay was also used to compare the photodynamic reactivity of light-reflective, microfine oxides TiO2, ZnO and ZrO2 suspended in aqueous 80% methanol. All of the microfine oxides (uncoated) showed greater photodynamic reactivity in equimolar dispersion than did any of the organic UVA- and UVB-absorbing sunscreens in homogeneous solution. In this assay the photodynamic oxidation rates for the microfine oxides decreased in the order ZnO ≫ TiO2 (anatase) 〉 ZrO2 〉 TiO2 (rutile). Resume Nous presentons un nouveau procede d'evaluation de l'activite photooxydante d'agents pour ecrans solaires base sur l'oxydation photodynamique de l'acide urique. L'acide urique a ete choisi comme test a l'oxydation en raison de sa forte reactivite a l'oxygene singulet et aux radicaux oxygene, sa haute sensibilite a la detection par les techniques electrochimiques (EC), sa faible capacite d'absorption de la lumiere, sa stabilite photochimique elevee dans le domaine UVA/UVB concerne, et sa stabilite a l'autooxydation. La demonstration du procede est effectuee au travers de l'oxydation photodynamique de l'acide urique co-irradie avec du Rose du Bengale, colorant phosensibilisateur tres efficace pour generer de l'oxygene singulet (1O2). En mettant ce test en oeuvre nous avons trouve que les vitesses relatives d'oxydation photodynamique d'ecrans solaires aux UVB dans due methanol a 80%, irradies avec une lumiere 〉 290nm, diminuent dans l'ordre: 2-ethylhexyl 4-dimethylamino-benzoate (DMABA-2EH) ≫ 2-ethylhexyl 4-methoxycinnamate (MCA-2EH) et les ecrans a l'essai: la 1-(1,1-dimethylethyl)-3-octanoyl-4,4-dimethyl-1,4,5,6-tetrahydopyridine (ICI-319) et la 1-(2-methylpropyl)-3-propionyl-4,4-dimethyl-1,4,5,6-tetrahydropyridine (ICI-855). les vitesses relatives d'oxydation photodynamique d'ecrans solaires aux UVA diminuent dans l'ordre: 4-tert-butyl-4'-methoxydibenzoylmethane (BMDBM) et 4-(2-propyl) benzophenone (PB) 〉 2-hydroxy-4'-methoxybenzophenone (HMB) et 2'2'-dihydroxy-4-methoxybenzophenone (DHMB). Nous avons confirme l'activite photdynamique du DMABA-2EH pour la production d'oxygene singulet (1O2) en utilisant la spectroscopie par resonance paramagnetique electronique et le reactif 2,2,6,6-tetramethyl-4-piperidone (4-oxo-TEMP). Nous n'avons pas pu detecter la production photodynamique des oxyradicaux du superoxyde (O2.) et du radical hydroxyle (HO.) a l'aide de la N-ter-butyl-a- phenylnitrone (PBN) en raison d'interferences photochimiques causees par ces reactifs spin-Bloquants. Le test de photooxydation de l'acide urique a aussi ete utilise pour comparer la reactivite photodynamique d'oxydes microfins reflechisseurs de lumiere TiO2, ZnO et ZrO2 en suspension dans du methanol aqueux a 80%. Tous ces oxydes microfins (non enrobes) ont montre une meilleure reactivite photodynamique en dispersion equimolaire que ne l'a fait aucun des ecrans solaires aux UVA et UVB en solution homogene. Lors de ce test les vitesses d'oxydation photodynamique des oxydes microfins ont diminue dans l'ordre ZnO ≫ TiO2 (anatase) 〉 ZrO2 〉 TiO2 (rutile).
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 63 (1998), S. 0 
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The application of microbubbles of pressured CO2 greatly increased CO2 concentration in the solution treated. By treatment at 6 MPa, 35°C and average residence time 15 min, L. brevis was completely inactivated at the level of dissolved CO2,γ≧ 11 (γ, Kuenen's gas absorption coefficient). E. coli and S. cerevisiae required γ≧ 17, and T. versatilis required γ≧ 21 for complete inactivation. Z. rouxii could be sterilized at 20 MPa and 26. A comparison of the continuous and batch method showed that L. brevis was inactivated completely under pressured CO2 〉 0.16 g/cm3 with the continuous method and 〉0.9 g/cm3 with the batch method.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Journal of neurochemistry 65 (1995), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: The effect of treatment with acute fluoxetine, a serotonin reuptake inhibitor, on the rate of serotonin synthesis in the rat brain was studied through autoradiography following intravenous administration of α-methyl-l-[3H]tryptophan. The rate of serotonin synthesis in fluoxetine-treated rats was compared with the rate measured in sham-treated rats (saline injection). Results showed a significant increase in the rate of synthesis in the majority of cerebral structures examined. The greatest increase (given as a percentage of rates in control animals) in the rate of serotonin synthesis was observed in the substantia nigra compacta (344%), hippocampus-CA3 (337%), dorsal hippocampus (283%), and caudate-putamen (232%). Fluoxetine had a less significant effect on the rate of synthesis in the pineal body (44%). Data suggest that acute fluoxetine treatment (30 mg/kg, i.p.) enhances the rate of serotonin synthesis in all the structures of rat brain examined in this work.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1365-2516
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Summary. Beta interferon therapy was given to seven chronic hepatitis C patients with haemophilia or other haemorrhagic disorders who had received clotting factor replacement therapy. Serum alanine aminotransferase (ALT) levels ranged from 82 to 275 UL-1 and hepatitis C virus (HCV)-RNA ranged from 106 to 109 copies mL-1. HCV-genotypes were I+II in one patient, II in one, II+III in four and IV in one. Patients received 6 mega units (MU) daily of natural type beta interferon by intravenous infusion for 6 weeks. In three of seven patients, the protocol was modified to intermittent administration because neutrocytopenia (under 500 × 106 L-1) developed in two patients and thrombocytopenia (under 50 × 109 L-1) was observed in one during treatment. No modification was necessary with regard to daily and total dose. All patients received administration without any haemorrhagic complications. Six of seven patients showed improvement in serum ALT levels, and one of the patients showed normalization of ALT levels for 6 months after treatment. HCV-RNA disappeared in four patients by the end of treatment, although no one remained negative 6 months after treatment. The results of our study were similar to those reported in previous papers which described the use of alpha interferon in haemophiliacs. The reason none of the patients showed sustained loss of HCV-RNA after therapy might be associated with high HCV-RNA levels, characteristics of the HCV-genotype and prolonged duration of the disease.
    Type of Medium: Electronic Resource
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