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1.
J Dent Res ; 100(10): 1047-1054, 2021 09.
Article in English | MEDLINE | ID: mdl-34157899

ABSTRACT

Biomaterials, once inserted in the oral cavity, become immediately covered by a layer of adsorbed proteins that consists mostly of salivary proteins but also of plasma proteins if the biomaterial is placed close to the gingival margin or if it becomes implanted into tissue and bone. It is often this protein layer, rather than the pristine biomaterial surface, that is subsequently encountered by colonizing bacteria or attaching tissue cells. Thus, to study this important initial protein adsorption from human saliva and serum and how it might be influenced through chemical modification of the biomaterial surface, we have measured the amount of protein adsorbed and analyzed the composition of the adsorbed protein layer using gel electrophoresis and western blotting. Here, we have developed an in vitro model system based on silica surfaces, chemically modified with 7 silane-based self-assembled monolayers that span a broad range of physicochemical properties, from hydrophilic to hydrophobic surfaces (water contact angles from 15° to 115°), low to high surface free energy (12 to 57 mN/m), and negative to positive surface charge (zeta potentials from -120 to +40 mV at physiologic pH). We found that the chemical surface functionalities exerted a substantial effect on the total amounts of proteins adsorbed; however, no linear correlation of the adsorbed amounts with the physicochemical surface parameters was observed. Only the adsorption behavior of a few singular protein components, from which physicochemical data are available, seems to follow physicochemical expectations. Examples are albumin in serum and lysozyme in saliva; in both, adsorption was favored on countercharged surfaces. We conclude from these findings that in complex biofluids such as saliva and serum, adsorption behavior is dominated by the overall protein-binding capacity of the surface rather than by specific physicochemical interactions of single protein entities with the surface.


Subject(s)
Saliva , Silicon Dioxide , Adsorption , Blood Proteins , Humans , Surface Properties
2.
J Dent Res ; 100(13): 1510-1519, 2021 12.
Article in English | MEDLINE | ID: mdl-34032471

ABSTRACT

Saliva has become an attractive body fluid for on-site, remote, and real-time monitoring of oral and systemic health. At the same time, the scientific community needs a saliva-centered information platform that keeps pace with the rapid accumulation of new data and knowledge by annotating, refining, and updating the salivary proteome catalog. We developed the Human Salivary Proteome (HSP) Wiki as a public data platform for researching and retrieving custom-curated data and knowledge on the saliva proteome. The HSP Wiki is dynamically compiled and updated based on published saliva proteome studies and up-to-date protein reference records. It integrates a wide range of available information by funneling in data from established external protein, genome, transcriptome, and glycome databases. In addition, the HSP Wiki incorporates data from human disease-related studies. Users can explore the proteome of saliva simply by browsing the database, querying the available data, performing comparisons of data sets, and annotating existing protein entries using a simple, intuitive interface. The annotation process includes both user feedback and curator committee review to ensure the quality and validity of each entry. Here, we present the first overview of features and functions the HSP Wiki offers. As a saliva proteome-centric, publicly accessible database, the HSP Wiki will advance the knowledge of saliva composition and function in health and disease for users across a wide range of disciplines. As a community-based data- and knowledgebase, the HSP Wiki will serve as a worldwide platform to exchange salivary proteome information, inspire novel research ideas, and foster cross-discipline collaborations. The HSP Wiki will pave the way for harnessing the full potential of the salivary proteome for diagnosis, risk prediction, therapy of oral and systemic diseases, and preparedness for emerging infectious diseases.Database URL: https://salivaryproteome.nidcr.nih.gov/.


Subject(s)
Proteome , Saliva , Humans
3.
Bioprocess Biosyst Eng ; 43(2): 193-205, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31549309

ABSTRACT

In 2004, the FDA published a guideline to implement process analytical technologies (PAT) in biopharmaceutical processes for process monitoring to gain process understanding and for the control of important process parameters. Viable cell concentration (VCC) is one of the most important key performance indicator (KPI) during mammalian cell cultivation processes. Commonly, this is measured offline. In this work, we demonstrated the comparability and scalability of linear regression models derived from online capacitance measurements. The linear regressions were used to predict the VCC and other familiar offline biomass indicators, like the viable cell volume (VCV) and the wet cell weight (WCW), in two different industrially relevant CHO cell culture processes (Process A and Process B). Therefore, different single-use bioreactor scales (50-2000 L) were used to prove feasibility and scalability of the in-line sensor integration. Coefficient of determinations of 0.79 for Process A and 0.99 for Process B for the WCW were achieved. The VCV was described with high coefficients of determination of 0.96 (Process A) and 0.98 (Process B), respectively. In agreement with other work from the literature, the VCC was only described within the exponential growth phase, but resulting in excellent coefficients of determination of 0.99 (Process A) and 0.96 (Process B), respectively. Monitoring these KPIs online using linear regression models appeared to be scale-independent, enabled deeper process understanding (e.g. here demonstrated in monitoring, the feeding profile) and showed the potential of this method for process control.


Subject(s)
Batch Cell Culture Techniques , Bioreactors , Electric Capacitance , Models, Biological , Animals , Biomass , CHO Cells , Cricetulus
4.
Mol Oral Microbiol ; 31(2): 175-88, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26172471

ABSTRACT

Salivary proteins modulate bacterial colonization in the oral cavity and interact with systemic pathogens that pass through the oropharynx. An interesting example is the opportunistic respiratory pathogen Streptococcus pneumoniae that normally resides in the nasopharynx, but belongs to the greater Mitis group of streptococci, most of which colonize the oral cavity. Streptococcus pneumoniae also expresses a serine-rich repeat (SRR) adhesin, PsrP, which is a homologue to oral Mitis group SRR adhesins, such as Hsa of Streptococcus gordonii and SrpA of Streptococcus sanguinis. As the latter bind to salivary glycoproteins through recognition of terminal sialic acids, we wanted to determine whether S. pneumoniae also binds to salivary proteins through possibly the same mechanism. We found that only a capsule-free mutant of S. pneumoniae TIGR4 binds to salivary proteins, most prominently to mucin MUC7, but that this binding was not mediated through PsrP or recognition of sialic acid. We also found, however, that PsrP is involved in agglutination of human red blood cells (RBCs). After removal of PsrP, an additional previously masked lectin-like adhesin activity mediating agglutination of sialidase-treated RBCs becomes revealed. Using a custom-spotted glycoprotein and neoglycoprotein dot blot array, we identify candidate glycan motifs recognized by PsrP and by the putative S. pneumoniae adhesin that could perhaps be responsible for pneumococcal binding to salivary MUC7 and glycoproteins on RBCs.


Subject(s)
Bacterial Capsules/metabolism , Mucins/metabolism , Salivary Proteins and Peptides/metabolism , Streptococcus pneumoniae/metabolism , Adhesins, Bacterial/genetics , Adhesins, Bacterial/metabolism , Antigens, Bacterial/immunology , Antigens, Bacterial/metabolism , Bacterial Adhesion/physiology , Hemagglutination/immunology , Humans , Immobilized Proteins , Membrane Proteins/immunology , Membrane Proteins/metabolism , Mouth/microbiology , Mucins/immunology , Mutation , N-Acetylneuraminic Acid/metabolism , Nasopharynx/microbiology , Salivary Proteins and Peptides/immunology , Streptococcus pneumoniae/genetics , Streptococcus pneumoniae/immunology , Streptococcus sanguis/genetics , Streptococcus sanguis/immunology , Streptococcus sanguis/metabolism
5.
Adv Dent Res ; 26(1): 7-14, 2014 May.
Article in English | MEDLINE | ID: mdl-24736699

ABSTRACT

Adequate salivary secretion is crucial to both oral and general health, since it provides a complex milieu for support of the microbial populations of the mouth, while at the same time containing antimicrobial products that help control these microbial populations. This paper summarizes several aspects of salivary component function, gland secretion mechanisms, and immunopathogenesis as related to oral health and disease. Salivary components mediate microbial attachment to oral surfaces, and also interact with planktonic microbial surfaces to facilitate agglutination and elimination of pathogens from the oral cavity. Adhesive interactions are often mediated by lectin-like bacterial proteins that bind to glycan motifs on salivary glycoproteins. An important salivary antimicrobial protein is histatin 5 (Hst 5), which shows potent and selective antifungal activity and also susceptibility to proteolytic degradation. Coupling of Hst 5 with the carrier molecule spermidine significantly enhanced killing of C. albicans and resistance to proteolytic degradation, compared with the parent peptide. Loss of salivary secretion may be caused by disorders such as Sjögren's syndrome (SS) or ectodermal dysplasia, or may be a side-effect of radiation therapy. Two new approaches to the treatment of salivary gland dysfunction include the use of resolvins and the creation of differentiated acinar structures to construct an artificial salivary gland. B-cells contribute to the pathogenesis of SS by releasing cytokines and autoantibodies and by influencing T-cell differentiation. CXCL13, a potent B-cell chemokine associated with autoimmune diseases, is elevated locally and systemically in SS and may represent a novel biomarker or therapeutic target in the management and treatment of SS.


Subject(s)
Saliva/microbiology , Salivary Glands/physiopathology , Candida albicans/metabolism , Candidiasis/drug therapy , Histatins/metabolism , Humans , Proteome
6.
Urologe A ; 50(12): 1578-83, 2011 Dec.
Article in German | MEDLINE | ID: mdl-22159703

ABSTRACT

This paper explains the concept of empathic leadership in the setting of fundamental organisational changes. It deals with the question of how you can establish a culture of leadership, which motivates employees positively and enthuses them for the upcoming changes. It discusses the basics of empathic leadership and considers the question of how handling of emotions influences change processes and how different management styles can be used supportively during changes. With the help of a practical example the different phases of change are presented from a management point of view. Thereby the theory of different levels of employee motivation is explained inter alia. The article shows that empathic leadership also has a lasting economic effect. This can be seen particularly in the power of motivation for change, in addition to recruitment and long-term employee retention.


Subject(s)
Delivery of Health Care/organization & administration , Empathy , Models, Organizational , Organizational Innovation/economics , Organizational Objectives/economics , Leadership
7.
Schweiz Arch Tierheilkd ; 151(7): 332-5, 2009 Jul.
Article in German | MEDLINE | ID: mdl-19565456

ABSTRACT

This case report describes the clinical, sonographic, computed tomographic and pathological findings in a 9-year-old goat with mediastinal lymphocytic thymoma. The goat was referred to the Department of Farm Animals because of weight loss and dyspnoea. The lead clinical findings were increased heart rate, increased respiratory rate and heart sounds heard only on the right side. Ultrasonographic examination revealed a massive amount of fluid and an echogenic corrugated mass ventral to the lungs in the thoracic cavity on the left side. Computed tomography showed that the mass was very large and diffusely mineralised. A tentative diagnosis of mediastinal neoplasia was made, and the goat was euthanized. Postmortem examination revealed a cauliflower-like, pedunculated tumour, which occupied the entire left thoracic cavity and displaced the left lung. Based on histological evaluation, the tumour was diagnosed as a lymphocytic thymoma.


Subject(s)
Goat Diseases/diagnosis , Mediastinal Neoplasms/veterinary , Thymoma/veterinary , Thymus Neoplasms/veterinary , Animals , Fatal Outcome , Goat Diseases/diagnostic imaging , Goats , Mediastinal Neoplasms/diagnosis , Mediastinal Neoplasms/diagnostic imaging , Thymoma/diagnostic imaging , Thymus Neoplasms/diagnosis , Thymus Neoplasms/diagnostic imaging , Tomography, X-Ray Computed/methods , Tomography, X-Ray Computed/veterinary , Ultrasonography/methods , Ultrasonography/veterinary
8.
Ophthalmologe ; 105(7): 656-60, 2008 Jul.
Article in German | MEDLINE | ID: mdl-18415108

ABSTRACT

BACKGROUND AND PURPOSE: Early glaucomatous visual field defects can occur outside the central 30 degrees , which is usually examined in perimetric tests used for glaucoma diagnosis and screening. This study aimed to evaluate the diagnostic value of peripheral suprathreshold stimulation in open angle glaucoma before the development of reproducible visual field damage in standard 30 degrees automatic white-on-white perimetry. METHODS: A total of 352 eyes of 352 patients (ages 35-69 years; visual acuity 0.8 or better) from the Erlanger Glaucoma Registry were included in this study. They were divided into two groups: normal eyes and preperimetric glaucoma. All patients underwent a standardized glaucoma examination including Octopus 500EZ static perimetry (G1 program, all three phases); 95 eyes of 95 patients also received a 135-point suprathreshold test pattern of the Humphrey Field Analyzer (model 750i) for detecting peripheral visual field defects. Sensitivity and specificity were calculated for any single test point in phase 3 of the G1 test pattern and the Humphrey 135-point pattern. A score was calculated, and cluster analysis was performed. RESULTS: In 33 of 176 (18.8%) eyes with preperimetric glaucoma, the score was 3 or higher in phase 3 of the G1 program (normal eyes: 19 of 196; 9.7%). For both examination modalities, the highest sensitivity was found in test locations in the superior nasal midperiphery, corresponding to neuroretinal rim loss predominantly in the inferotemporal sector in early glaucomatous optic disc atrophy. CONCLUSION: Positive test results using suprathreshold stimulation in the midperiphery can be found in patients with preperimetric glaucoma at a significantly higher frequency than in normal subjects. Longitudinal studies will show whether such tests can be useful for predicting perimetric manifestation of the disease.


Subject(s)
Glaucoma/diagnosis , Photic Stimulation/methods , Visual Field Tests/methods , Female , Humans , Male , Middle Aged , Reproducibility of Results , Sensitivity and Specificity
9.
J Biomed Mater Res A ; 84(3): 817-27, 2008 Mar 01.
Article in English | MEDLINE | ID: mdl-17635034

ABSTRACT

Silicon wafers modified by silanisation with different functional groups are used to study the bioactivity of surfaces with varying physicochemical properties. Oxidation of the wafers created very hydrophilic surfaces, and moderately wettable surfaces were produced by coating with poly(ethylene glycol) (PEG). Immobilization of hydrocarbon chains to the wafers produced hydrophobic surfaces, and hydrophobicity was further increased by fluorocarbon coatings. The oxidized and the hydrocarbon-modified surfaces supported the adhesion of human MG-63 osteoblasts and 3T3 mouse fibroblasts as well as Staphylococcus aureus 8325-4. Adhesion of osteoblasts and fibroblasts, however, was decreased on highly hydrophobic fluorocarbon surfaces, whereas adhesion of S. aureus was supported. Coating of the fluorocarbon surface with fibronectin increased the number of attached eukaryotic cells, but the accumulation of bacteria remained unchanged. In contrast, surface coatings with PEG-groups inhibited the binding of S. aureus; however, the adhesion of the eukaryotic cells was high. The number of S. aureus on PEG-modified surfaces covered with fibronectin increased about twofold, yet it was still decreased to 25-30% related to the number of bacteria on other surfaces. These findings provide evidence that the PEG-modified surfaces showed selective bioactivity, preventing the attachment of a microbial pathogen but supporting the adhesion of eukaryotic cells.


Subject(s)
Bacterial Adhesion/physiology , Eukaryotic Cells/physiology , Models, Biological , Silicon , Staphylococcus aureus/physiology , 3T3 Cells , Animals , Cell Adhesion/physiology , Cell Line, Tumor , Humans , Mice , Staphylococcus epidermidis , Surface Properties , Wettability
10.
Toxicology ; 242(1-3): 71-9, 2007 Dec 05.
Article in English | MEDLINE | ID: mdl-17964704

ABSTRACT

The genus Erythrina (Leguminosae), consisting of over 100 different species, is distributed in tropical regions. In traditional medicine, Erythrina species are used to treat cancer, but little is known about the anticancer mechanisms. From the stem bark of Erythrina addisoniae Hutch. & Dalziel, six prenylated pterocarpans were isolated and analysed for pharmacological activity: While calopocarpin, cristacarpin, orientanol c, and isoneorautenol showed only a weak or moderate toxicity in H4IIE hepatoma cells (EC(50)-value> 25 microM), the toxicity of neorautenol and phaseollin was in the low micromolar range (EC(50)-value: 1 and 1.5 microM, respectively). We further focused on these two substances showing that both increased caspase 3/7 activity and nuclear fragmentation as markers for apoptotic cell death. Neorautenol (10 microM, 2h), but not phaseollin induced the formation of DNA strand breaks (comet assay). Both substances showed no effect on NF-kappaB signalling (SEAP assay: basal activity and stimulation with TNF-alpha), on the other hand both pterocarpans (10 microM, 2 h) decreased the activation of the ERK kinase (p44/p42), an mitogen activated protein kinase which is associated with cell proliferation. We conclude that the pterocarpans phaseollin and neorautenol may be responsible for the anticarcinogenic actions of the plant extract reported in the literature. Further analysis of these substances may lead to new pharmacons to be used in cancer therapy.


Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , Apoptosis/drug effects , Erythrina , Extracellular Signal-Regulated MAP Kinases/metabolism , Isoflavones/pharmacology , Plant Extracts/pharmacology , Pterocarpans/pharmacology , Signal Transduction/drug effects , Animals , Antineoplastic Agents, Phytogenic/isolation & purification , Caspase 3/metabolism , Caspase 7/metabolism , Cell Line, Tumor , Cell Survival/drug effects , DNA Breaks, Single-Stranded , Dose-Response Relationship, Drug , Enzyme Activation , Erythrina/chemistry , Inhibitory Concentration 50 , Isoflavones/isolation & purification , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/metabolism , NF-kappa B/metabolism , Necrosis , Phosphorylation , Plant Bark , Plant Extracts/isolation & purification , Prenylation , Pterocarpans/isolation & purification , Pterocarpans/toxicity , Rats
11.
J Dent Res ; 84(1): 29-34, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15615871

ABSTRACT

During the first year of an infant's life, the oral environment is subject to drastic changes that coincide with the eruption of teeth. Proteins in saliva are important for protecting oral surfaces and provide receptors for bacterial adhesins. The objective of this longitudinal study was to monitor the general composition and expression of proteins in whole saliva of infants, to prove the hypothesis that expression of certain proteins changes during infant development, and might be associated with tooth eruption. The results showed a remarkable constancy in the overall pattern of salivary proteins and glycoproteins during infancy. Exceptions were the mucins and albumin. The mucins are expressed differentially, with first MUC7 and later MUC5B being predominant. Albumin, a marker of serum leakage, started to rise in whole saliva preceding tooth eruption. Thus, the expression of only few proteins appears to be changed during infant development.


Subject(s)
Salivary Proteins and Peptides/biosynthesis , Albumins/biosynthesis , Blotting, Western , Electrophoresis, Polyacrylamide Gel , Humans , Immunoglobulin A, Secretory/biosynthesis , Infant , Longitudinal Studies , Mucins/biosynthesis , Statistics, Nonparametric , Tooth Eruption , alpha-Amylases/biosynthesis
12.
J Dent Res ; 83(6): 505-10, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15153461

ABSTRACT

Colonization of the tooth surface by actinomyces and viridans group streptococci involves the attachment of these bacteria to adsorbed salivary components of the acquired enamel pellicle. The hypothesis that this attachment depends on specific adhesins has now been assessed from the binding of bacteria with well-defined adhesive properties to blots of SDS-PAGE-separated parotid and submandibular-sublingual (SM-SL) saliva. Streptococcus sanguis and type 2 fimbriated Actinomyces naeslundii, which bound terminal sialic acid and Galbeta1-3GalNAc, respectively, recognized only a few SM-SL salivary components, primarily MG2. In contrast, type 1 fimbriated A. naeslundii and S. gordonii, which bound purified proline-rich proteins (PRPs), recognized several other components from both SM-SL and parotid saliva. Significantly, bacteria that lacked PRP-binding and the lectin-like activities detected by binding to MG2 failed to bind any immobilized salivary component. These findings suggest the involvement of specific adhesins in bacterial recognition of many adsorbed salivary proteins and glycoproteins.


Subject(s)
Actinomyces/metabolism , Adhesins, Bacterial/metabolism , Lectins/metabolism , Mouth/microbiology , Peptides/metabolism , Phosphoproteins/metabolism , Proline/metabolism , Salivary Proteins and Peptides/metabolism , Streptococcus sanguis/metabolism , Bacterial Adhesion , Dental Pellicle/metabolism , Electrophoresis, Polyacrylamide Gel , Fimbriae, Bacterial/metabolism , Glycoproteins/metabolism , Humans , Proline-Rich Protein Domains , Protein Binding , Streptococcus/metabolism
13.
J Dent Res ; 83(4): 322-6, 2004 Apr.
Article in English | MEDLINE | ID: mdl-15044507

ABSTRACT

Little is known about the involvement of saliva in gingival overgrowth (GO). It was hypothesized that, in this situation, the composition of saliva is altered. Thus, proteins, albumin, cytokines, and growth factors in whole and glandular saliva were investigated. Differences between glandular and gingival contributions to the composition of saliva were explored in patients medicated with cyclosporin who exhibited GO (responders), those without GO (non-responders), and non-medicated subjects (controls). In whole saliva, interleukin-1alpha (IL-1alpha), IL-6, IL-8, epidermal growth factor (EGF), nerve growth factor (NGF), and albumin were detected, but in glandular saliva only EGF and NGF were identified. Albumin and IL-6 differed significantly between responders and controls, although the overall profile of salivary proteins remained unchanged. Thus, inflammatory cytokines and albumin are confined to whole saliva and are associated with GO, whereas its content of EGF and NGF appears unaffected by cyclosporin.


Subject(s)
Albumins/metabolism , Cytokines/metabolism , Gingival Overgrowth/metabolism , Saliva/metabolism , Salivary Proteins and Peptides/metabolism , Albumins/analysis , Cyclosporine , Cytokines/analysis , Epidermal Growth Factor/analysis , Epidermal Growth Factor/metabolism , Gingival Overgrowth/chemically induced , Humans , Interleukins/analysis , Interleukins/metabolism , Male , Nerve Growth Factor/analysis , Nerve Growth Factor/metabolism , Saliva/chemistry , Salivary Proteins and Peptides/analysis
14.
Oral Microbiol Immunol ; 17(4): 257-62, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12121477

ABSTRACT

The binding of 10 viridans group streptococci to sialic acid-, galactose (Gal)- and N-acetylgalactosamine (GalNAc)-containing receptors was defined by analysis of the interactions between these bacteria and structurally defined glycoconjugates, host cells and other streptococci. All interactions with sialic acid-containing receptors were Ca(2+)-independent as they were not affected by ethyleneglycoltetraacetic acid (EGTA), whereas all interactions with Gal- and GalNAc-containing receptors were Ca(2+)-dependent. Recognition of sialic acid-, Gal- and GalNAc-containing receptors varied widely among the strains examined, in a manner consistent with the association of each of the three lectin-like activities with a different bacterial cell surface component.


Subject(s)
Bacterial Adhesion/physiology , Glycoconjugates/metabolism , Receptors, Cell Surface/metabolism , Receptors, Immunologic/metabolism , Viridans Streptococci/physiology , Acetylgalactosamine/metabolism , Biofilms , Calcium/metabolism , Galactose/metabolism , N-Acetylneuraminic Acid/metabolism
15.
Acta Crystallogr C ; 57(Pt 4): 444-5, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11313590

ABSTRACT

The reaction of dimedone with 2,6-dichlorobenzaldehyde leads to the title compound, C(23)H(26)Cl(2)O(4). In principle, the reaction could yield eight different stereoisomers. We have found four of them in the same crystal as two enantiomeric pairs of diastereomers, which means that the asymmetric unit is built up of two different diastereomers. Two of the three chiral centres display the same configuration, while the third is different in the two molecules in the asymmetric unit. The packing of the molecules is stabilized by hydrogen bonds between the hydroxy group and the carbonyl group attached to the cyclohexene ring, forming chains in which the different diastereomers alternate.

16.
Acta Crystallogr C ; 57(Pt 4): 446-51, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11313591

ABSTRACT

We have determined the crystal structures of 2,2'-(4-fluorophenyl)methylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexen-1-one), C(23)H(27)FO(4), (I), 2,2'-(4-chlorophenyl)methylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexen-1-one), C(23)H(27)ClO(4), (II), 2,2'-(4-hydroxyphenyl)methylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexen-1-one), C(23)H(28)O(5), (III), 2,2'-(4-methylphenyl)methylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexen-1-one), C(24)H(30)O(4), (IV), 2,2'-(4-methoxyphenyl)methylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexen-1-one), C(24)H(30)O(5), (V), and 2,2'-(4-N,N'-dimethylaminophenyl)methylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexen-1-one), C(25)H(33)NO(4), (VI). Structures (III) to (VI) of these bis-dimedone derivatives show nearly the same packing pattern irrespective of the different substituent in the para position of the aromatic ring. However, (II) does not fit into this scheme, although the Cl atom is a substituent not too different from the others. The different packing of the fluoro compound, (I), can be explained by the fact that it crystallizes with two molecules in the asymmetric unit, which show a different conformation of the dimedone ring. On the other hand, (I) shows a similar packing pattern to bis(2-hydroxy-4,4-dimethyl-6-oxo-1-cyclohexenyl)phenylmethane, a compound containing an aromatic ring without any substituent and with Z' = 2.

17.
Infect Immun ; 68(11): 6346-54, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11035744

ABSTRACT

Interactions of oral streptococci and actinomyces with polymorphonuclear leukocytes (PMNs), mediated by sialic acid- and Gal/GalNAc-reactive adhesins, respectively, result in activation of the PMNs and thereby may contribute to the initiation of oral inflammation. Sialidase treatment of PMNs or HL-60 cells abolished adhesion of Streptococcus gordonii but was required for adhesion of Actinomyces naeslundii. The same effects of sialidase were noted for adhesion of these bacteria to a major 150-kDa surface glycoprotein of either PMNs or undifferentiated HL-60 cells and to a 130-kDa surface glycoprotein of differentiated HL-60 cells. These glycoproteins were both identified as leukosialin (CD43) by immunoprecipitation with a specific monoclonal antibody (MAb). Adhesion of streptococci and actinomyces to a 200-kDa minor PMN surface glycoprotein was also detected by bacterial overlay of untreated and sialidase-treated nitrocellulose transfers, respectively. This glycoprotein was identified as leukocyte common antigen (CD45) by immunoprecipitation with a specific MAb. CD43 and CD45 both possess extracellular mucinlike domains in addition to intracellular domains that are implicated in signal transduction. Consequently, the interactions of streptococci and actinomyces with the mucinlike domains of these mammalian cell surface glycoproteins result not only in adhesion but, in addition, may represent the initial step in PMN activation by these bacteria.


Subject(s)
Actinomyces/physiology , Adhesins, Bacterial/metabolism , Antigens, CD , Glycoproteins/analysis , Neutrophils/chemistry , Receptors, Immunologic/analysis , Streptococcus/physiology , HL-60 Cells , Humans , Leukocyte Common Antigens/analysis , Leukosialin , Neutrophils/microbiology , Sialoglycoproteins/analysis
18.
Acta Crystallogr C ; 56 (Pt 5): 607-9, 2000 May.
Article in English | MEDLINE | ID: mdl-10851636
20.
Acta Crystallogr C ; 56(Pt 4): E162-3, 2000 Apr 15.
Article in English | MEDLINE | ID: mdl-15263194

ABSTRACT

The title compound, C(11)H(15)N(3)O, crystallizes with two molecules in the asymmetric unit, which are held together by an extended network of hydrogen bonds. It is remarkable that only five of the six theoretically possible hydrogen bonds are formed.

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