| 1. |
- Christakopoulos, Paul, et al.
(author)
-
Antimicrobial activity of acidic xylo-oligosaccharides produced by family 10 and 11 endoxylanases
- 2003
-
In: International Journal of Biological Macromolecules. - 0141-8130 .- 1879-0003. ; 31:4-5, s. 171-175
-
Journal article (peer-reviewed)abstract
- Acidic oligosaccharides were obtained from birchwood xylan by treatment with a Thermoascus aurantiacus family 10 and a Sporotrichum thermophile family 11 endoxylanases. The main difference between the products liberated by xylanases of family 10 and 11 concerned the length of the products containing 4-O-methyl-d-glucuronic acid. The xylanase from T. aurantiacus liberate from glucuronoxylan an aldotetrauronic acid as the shortest acidic fragment in contrast with the enzyme from S. thermophile, which liberated an aldopentauronic acid. Acidic xylooligosaccharides were separated from the hydrolysate by anion-exchange and size-exclusion chromatography (SEC) and the primary structure was determined by 13C NMR spectroscopy. The acidic xylo-oligosaccharides were tested against three Gram-positive and three Gram-negative aerobically grown bacteria, as well as against Helicobacterpylori. Aldopentauronic acid was proved more active against the Gram-positive bacteria and against H. pylori.
|
|
| 2. |
- Rosdahl, Hans, et al.
(author)
-
A microdialysis method for the in situ investigation of the action of large peptide molecules in human skeletal muscle : detection of local metabolic effects of insulin.
- 2000
-
In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 28:1, s. 69-73
-
Journal article (peer-reviewed)abstract
- The possibility of using microdialysis catheters with a large pore size dialysis membrane (100 kDa) to investigate the action of macromolecules perfused into the interstitial space of peripheral tissues was explored. This was made possible by increasing the colloid osmotic pressure of the perfusate with 40 g/l of dextran-70 to prevent perfusate loss across the dialysis membranes. Microdialysis catheters were inserted into the quadriceps femoris muscle of 13 human subjects. With different perfusion flow rates (1. 33, 0.66, 0.33 and 0.16 microl/min) the recorded concentrations of glucose, lactate, and urea were in agreement with values previously obtained using a conventional membrane with a smaller pore size (20 kDa) [Rosdahl H, Hamrin K, Ungerstedt U, Henriksson. J Am J Physiol 1998;274:E936-45.]. When insulin was added to the perfusate, the concentration of glucose was significantly reduced, indicating that insulin diffuses across the dialysis membrane and has cellular effects that can be simultaneously recorded. The present findings are the first documentation on the use of microdialysis to study the local metabolic action of large peptide molecules in human tissues and may open new avenues for in-vivo metabolic research.
|
|
| 3. |
- Sanakis, Y., et al.
(author)
-
Catechol 1,2-dioxygenase from Pseudomonas putida in organic media : an electron paramagnetic resonance study
- 2003
-
In: International Journal of Biological Macromolecules. - 0141-8130 .- 1879-0003. ; 33:1-3, s. 101-106
-
Journal article (peer-reviewed)abstract
- The ability of an isolated isozyme of catechol 1,2-dioxygenase from Pseudomonas putida DSM 437 to function in a non-aqueous environment was investigated. The lyophilized enzyme is able to keep its catalytic function catalyzing the oxidation of catechol in n-hexane. Electron paramagnetic resonance (EPR) spectroscopy at liquid helium temperatures was applied to compare the properties of the non-heme iron of the enzyme in the organic solvent and in the aqueous solution. The catalytic performance of the enzyme in the organic solvent is correlated with the spectroscopic properties of the non-heme iron.
|
|
| 4. |
- Vardakou, Maria, et al.
(author)
-
Mode of action of family 10 and 11 endoxylanases on water-unextractable arabinoxylan
- 2003
-
In: International Journal of Biological Macromolecules. - 0141-8130 .- 1879-0003. ; 33:1-3, s. 129-134
-
Journal article (peer-reviewed)abstract
- Microbial endo-β-1,4-xylanases (EXs, EC 3.2.1.8) belonging to glycanase families 10 and 11 differ in their action on water-unextractable arabinoxylan (WU-AX). WU-AX was incubated with different levels of a Thermoascus aurantiacus family 10 and a Sporotrichum thermophile family 11 endoxylanases. At 10 g l−1 arabinoxylan, enzyme concentrations (KE values) needed to obtain half-maximal hydrolysis rates (Vmax values) were 4.4 nM for the xylanase from T. aurantiacus and 7.1 nM for the xylanase from S. thermophile. Determination of Vmax/KE revealed that the family 10 enzyme hydrolysed two times more efficiently WU-AX than the family 11 enzyme. Molecular weights of the products formed were assessed and separation of feruloyl-oligosaccharides was achieved by anion-exchange and size-exclusion chromatography (SEC). The main difference between the feruloylated products by xylanases of family 10 and 11 concerned the length of the products containing feruloyl-arabinosyl substitution. The xylanase from T. aurantiacus liberated from WU-AX a feruloyl arabinoxylodisaccharide (FAX2) as the shortest feruloylated fragment in contrast with the enzyme from S. thermophile, which liberated a feruloyl arabinoxylotrisaccharide (FAX3). These results indicated that different factors govern WU-AX breakdown by the two endoxylanases.
|
|
| 5. |
- Ekström, Jörgen, et al.
(author)
-
Nitric oxide-dependent mitotic activity in salivary glands of the rat upon sympathetic stimulation
- 2004
-
In: Archives of Oral Biology. - : Elsevier. - 0003-9969 .- 1879-1506. ; 49:11, s. 889-894
-
Journal article (peer-reviewed)abstract
- Incorporation of [3H]thymidine into trichloroacetic acid (TCA)-insoluble material of the parotid and submandibular glands was used as an index of mitotic activity following unilateral electrical stimulation of the sympathetic innervation (20 Hz, 4 min every fifth minute over 34 min). Stimulation under β-adrenoceptor blockade (propranolol 2 mg/kg, intravenous) alone or combined with α-adrenoceptor blockade (phentolamine 2 mg/kg, intravenous) did not increase the rate of [3H]thymidine incorporation into the two types of glands. However, under α-adrenoceptor blockade the [3H]thymidine incorporation increased into the parotid glands, by 122% (compared to the glands on the contralateral side), but not into the submandibular glands. In the presence of the neuronal type NO-synthase (nNOS) blocker N-PLA (30 mg/kg, intravenous) or the unselective NO-synthase blocker L-NAME (30 mg/kg, intravenous), this increase was reduced to 49 and 47%, respectively. Thus, the major part of the sympathetically nerve-evoked β-adrenoceptor-mediated mitotic response was found to depend on the activity of neuronal type NO-synthase to generate NO. Since the sympathetic nerve fibres of the parotid gland lack NO-synthase, the neuronal type NO-synthase subjected to the inhibitors is likely to be of parenchymal origin. © 2004 Elsevier Ltd. All rights reserved.
|
|
| 6. |
- Götrick, Bengt, et al.
(author)
-
The xerogenic potency and mechanism of action of tramadol inhibition of salivary secretion in rats.
- 2004
-
In: Archives of oral biology. - : Elsevier BV. - 0003-9969 .- 1879-1506. ; 49:12, s. 969-73
-
Journal article (peer-reviewed)abstract
- Tramadol is a centrally acting analgesic with weak opioid agonist properties, which also has monoaminergic activity, exerted via inhibition of neuronal uptake of serotonin and norepinephrine. Tramadol is generally well tolerated and the most common adverse events are nausea, dizziness, drowsiness, sweating, vomiting and dry mouth. Currently it was examined by which principal mechanism tramadol induces oral dryness. The effects of intravenous administration (+/-)-tramadol were studied in rats on the flow of saliva in response to a peripheral cholinergic stimulus or to reflex activation involving the relay of impulses in the central nervous system. In pentobarbitone-anaesthetized rats, the salivary secretion to acetylcholine (0.1-10 micromol/kg IV) was increased by up to 110% by tramadol (1-5 mg/kg IV) and the protein concentration therein by up to 400%. The administration alpha- and beta-adrenoceptor antagonists resulted in almost identical acetylcholine-evoked responses as in the absence of tramadol. The secretory response to the application of citric acid on the tongue of the rat was reduced by 38% and by 64%, respectively, at 5 and 10 mg/kg IV of tramadol (p < 0.05-0.01). Thus, tramadol exerts its principal xerogenic effect by activating inhibitory pathways in the central nervous system and has no anticholinergic effect on the salivary glands at dosages that may be clinically relevant. Furthermore, the tramadol-induced increase of the acetylcholine-evoked secretion occurred at a glandular level and depended most likely on a release of noradrenaline from glandular nerve terminals.
|
|
| 7. |
- Jönsson, Daniel, et al.
(author)
-
Immunocytochemical demonstration of estrogen receptor beta in human periodontal ligament cells.
- 2004
-
In: Archives of Oral Biology. - 1879-1506 .- 0003-9969. ; 49:1, s. 85-88
-
Journal article (peer-reviewed)abstract
- Two transcription associated estrogen receptor (ER) subtypes have been identified and named ERα and ERβ. In the present study we investigate the expression of these ER subtypes in cultured human periodontal ligament (PDL) cells by immunocytochemistry. ERβ immunoreactivity was observed in the nuclei of about 40% of the PDL cells, while no ERα immunoreactivity was detected. In human breast cancer MCF-7 cells, serving as positive controls, both ERα and ERβ immunoreactivities were demonstrated. No immunoreactivity was observed after omission of the primary antibodies. This study suggests that estrogen acts on gene transcription preferentially via ERβ in human PDL cells.
|
|
| 8. |
- Mislovicova, D, et al.
(author)
-
Influence of mannan epitopes in glycoproteins - Concanavalin A interaction. Comparison of natural and synthetic glycosylated proteins
- 2002
-
In: International Journal of Biological Macromolecules. - 1879-0003. ; 30:5, s. 251-258
-
Journal article (peer-reviewed)abstract
- Two natural glycoproteins/glycoenzymes, invertase and glucoamylase, and two neoglycoconjugates, synthetized from Saccharomyces cerevisiae mannan, bovine serum albumin and penicillin G acylase were tested for interaction with lectin Concanavalin A (Con A). The interaction of natural and synthetic glycoproteins with Con A was studied using three different experimental methods: (i) quantitative precipitation in solution (ii) sorption to Con A immobilized on bead cellulose; and (iii) kinetic measurement of the interaction by surface plasmon resonance. Prepared neoglycoproteins were further characterized: saccharide content, molecular weight, polydispersion, kinetic and equilibrium association constants with Con A were determined. It can be concluded that the used conjugation method proved to be able to produce neoglycoproteins with similar properties like natural glycoproteins, i.e. enzymatic activity (protein part) and lectin binding activity (mannan part) were preserved and the neoglycoconjugates interact with Con A similarly as natural mannan-type glycoproteins.
|
|
| 9. |
- Sonesson, Mikael, et al.
(author)
-
Minor salivary gland secretion in children and adults
- 2003
-
In: Archives of Oral Biology. - : Elsevier. - 0003-9969 .- 1879-1506. ; 48:7, s. 535-539
-
Journal article (peer-reviewed)abstract
- The minor salivary glands are of great importance in the physiology and pathology of the oral cavity. So far, studies of the minor glands have concentrated on adults. In the present study, minor salivary gland secretion was studied in the buccal and labial mucosa of 3-year-old children, adolescents and young adults. In addition, the number of glands per surface area was assessed in the labial mucosa. A total of 90 individuals were included, 30 in each age-group. Saliva was collected on filter paper discs and the salivary secretion rate was measured using a Periotron 8000. The number of secreting labial glands was assessed on PAS-stained filter paper discs under a microscope. Salivary secretion in the buccal mucosa was found to be age-related, with a statistically significant lower rate of secretion (P=0.003) in the 3-year-olds (mean 7.7 microl x cm(-2) x min(-1)) compared with the young adults (11.9 microl x cm(-2) x min(-1)). No significant differences between the sexes were noted. For the labial glands, no age- or sex-related differences were found. In all age-groups, salivary secretion was significantly higher in the buccal than in the labial mucosal area. A statistically significant difference in number of secreting glands was found between all age-groups, with a decreasing number of glands per surface unit with age. The number of glands was significantly lower in males compared with females in the group of adults. The lower rate of buccal salivary secretion in the young children may imply that the oral mucosa is more vulnerable to external injury and that caries protection on the buccal molar surfaces is lower. Previous studies indicate that adults with a reduced rate of minor salivary gland secretion are more susceptible to caries.
|
|
| 10. |
- Rothenbacher, D, et al.
(author)
-
Relationship between infectious burden, systemic inflammatory response, and risk of stable coronary artery disease: role of confounding and reference group
- 2003
-
In: Atherosclerosis. - 1879-1484. ; 170:2, s. 339-345
-
Journal article (peer-reviewed)abstract
- Aim: The purpose of the study was to assess the association between seropositivity to various infectious agents and stable coronary artery disease (CAD), controlling simultaneously for a variety of potential confounders. We also investigated whether the choice of a larger reference group might affect the results, and whether or not seropositivity to multiple agents was associated with a systemic inflammatory response. Methods: We assessed the simultaneous prevalence of antibodies against Helicobacter pylori, Chlamydia, cytomegalovirus, and herpes simplex virus in 312 patients with angiographically proven coronary artery disease (CAD) and in 479 age and sex matched controls. C-reactive protein, interleukin-6, fibrinogen, PAI- I -activity, D-dimer, von Willebrand Factor, plasma viscosity, and a complete blood cell count were determined in all subjects. Results: Seropositivity to all of the four agents was 21.8% in cases and 13.6% in controls (P = 0.0003). We found a dose-response relationship between combined IgG-seropositivity to H. pylori, Chlamydia, cytomegalovirus, and herpes simplex virus and odds for the presence of angiographically confirmed stable CAD which, however, was strongly reduced after controlling for a variety of potential confounders. The dose-response pattern was no longer evident if a more stable reference group (subjects seropositive for two agents) was used instead of the relatively small reference group with zero or one seropositivity. We found no consistent pattern between IgG-seropositivity to several pathogens and inflammatory markers. Conclusions: Based on serological evidence of various infectious agents, this study suggests that the aggregate number of persistent infections is not independently associated with an increased risk for CAD if control for confounding and use of a stable reference group are guaranteed. (C) 2003 Published by Elsevier Ireland Ltd.
|
|
