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1.
BMC Cancer ; 24(1): 513, 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38654241

ABSTRACT

BACKGROUND: [18F]FDG-PET/CT is used for staging and treatment planning in patients with locally advanced cervical cancer (LACC). We studied if a PET-based prediction model could provide additional risk stratification beyond International Federation of Gynaecology and Obstetrics (FIGO) staging in our population with LACC to aid treatment decision making. METHODS: In total, 183 patients with LACC treated with chemoradiation between 2013 and 2018 were included. Patients were treated according to FIGO 2009 and retrospectively reclassified according to FIGO 2018 staging system. After validation of an existing PET-based prediction model, the predicted recurrent free survival (RFS), disease specific survival (DSS) and overall survival (OS) at 1, 3, and 5 years, based on metabolic tumor volume (MTV), maximum standardized uptake value (SUVmax) and highest level of [18F]FDG-positive node was calculated. Then the observed survival was compared to the predicted survival. An area under the curve (AUC) close to or higher than 0.7 was considered adequate for accurate prediction. The Youden (J) index defined survival chance cutoff values for low and high risk groups. RESULTS: All AUC values for the comparison between predicted and observed outcomes were > 0.7 except for 5-year RFS and for 5-year OS which were close to 0.7 (0.684 and 0.650 respectively). Cutoff values for low and high risk survival chance were 0.44 for the 3-year RFS and 0.47 for the 5-year OS. The FIGO 2009 system could not differentiate between the risk profiles. After reclassification according to FIGO 2018, all patients with stage IIIC2 and IVB fell in the high risk and almost all patients with stages IB2-IIIB and IVA in the low risk group. In patients with stage IIIC1 disease the FIGO stage cannot discriminate between the risk profiles. CONCLUSIONS: Low and high risk patients with LACC can be identified with the PET-based prediction model. In particular patients with stage IIIC1 need additional risk stratification besides the FIGO 2018 staging. The Kidd model could be a useful tool to aid treatment decision making in these patients. Our results also support the choice of [18F]FDG-PET/CT imaging in patients with LACC.


Subject(s)
Fluorodeoxyglucose F18 , Neoplasm Staging , Positron Emission Tomography Computed Tomography , Uterine Cervical Neoplasms , Humans , Female , Uterine Cervical Neoplasms/diagnostic imaging , Uterine Cervical Neoplasms/pathology , Uterine Cervical Neoplasms/mortality , Uterine Cervical Neoplasms/therapy , Positron Emission Tomography Computed Tomography/methods , Middle Aged , Retrospective Studies , Adult , Aged , Risk Assessment/methods , Chemoradiotherapy , Radiopharmaceuticals , Aged, 80 and over , Prognosis
2.
Dev Cogn Neurosci ; 66: 101347, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38277712

ABSTRACT

While it is well established that grammar learning success varies with age, the cause of this developmental change is largely unknown. This study examined functional MRI activation across a broad developmental sample of 165 Dutch-speaking individuals (8-25 years) as they were implicitly learning a new grammatical system. This approach allowed us to assess the direct effects of age on grammar learning ability while exploring its neural correlates. In contrast to the alleged advantage of children language learners over adults, we found that adults outperformed children. Moreover, our behavioral data showed a sharp discontinuity in the relationship between age and grammar learning performance: there was a strong positive linear correlation between 8 and 15.4 years of age, after which age had no further effect. Neurally, our data indicate two important findings: (i) during grammar learning, adults and children activate similar brain regions, suggesting continuity in the neural networks that support initial grammar learning; and (ii) activation level is age-dependent, with children showing less activation than older participants. We suggest that these age-dependent processes may constrain developmental effects in grammar learning. The present study provides new insights into the neural basis of age-related differences in grammar learning in second language acquisition.

3.
Prep Biochem Biotechnol ; : 1-8, 2023 Dec 13.
Article in English | MEDLINE | ID: mdl-38088914

ABSTRACT

Telomere Length (TL) and integrity is significantly associated with age-related disease, multiple genetic and environmental factors. We observe mouse genomic DNA (gDNA) isolation methods to have a significant impact on average TL estimates. The canonical qPCR method does not measure TL directly but via the ratio of telomere repeats to a single copy gene (SCG) generating a T/S ratio. We use a monochromatic-multiplex-qPCR (mmqPCR) method which multiplexes the PCR and enables quantification of the target and the single copy gene within the same qPCR reaction. We demonstrate that TL measurements, from murine gDNA, isolated via Spin Columns (SC) and Magnetic Beads (MB), generate significantly smaller T/S ratios compared to gDNA isolated via traditional phenol/chloroform methods. The former methods may impede correct TL estimation by producing non representative fragment sets and reducing qPCR efficacy. This work highlights discrepancies in TL measurements due to different extraction techniques. We recommend the use of gDNA isolation methods that are shown to preserve DNA length and integrity, such as phenol/chloroform isolation. We propose that widely used high throughput DNA isolation methodologies can create spurious associations within a sample set, thus creating misleading data. We suggest that published TL associations should be revisited in the light of these data.

4.
BMC Psychol ; 10(1): 169, 2022 Jul 08.
Article in English | MEDLINE | ID: mdl-35804430

ABSTRACT

BACKGROUND: While it is well established that second language (L2) learning success changes with age and across individuals, the underlying neural mechanisms responsible for this developmental shift and these individual differences are largely unknown. We will study the behavioral and neural factors that subserve new grammar and word learning in a large cross-sectional developmental sample. This study falls under the NWO (Nederlandse Organisatie voor Wetenschappelijk Onderzoek [Dutch Research Council]) Language in Interaction consortium (website: https://www.languageininteraction.nl/ ). METHODS: We will sample 360 healthy individuals across a broad age range between 8 and 25 years. In this paper, we describe the study design and protocol, which involves multiple study visits covering a comprehensive behavioral battery and extensive magnetic resonance imaging (MRI) protocols. On the basis of these measures, we will create behavioral and neural fingerprints that capture age-based and individual variability in new language learning. The behavioral fingerprint will be based on first and second language proficiency, memory systems, and executive functioning. We will map the neural fingerprint for each participant using the following MRI modalities: T1-weighted, diffusion-weighted, resting-state functional MRI, and multiple functional-MRI paradigms. With respect to the functional MRI measures, half of the sample will learn grammatical features and half will learn words of a new language. Combining all individual fingerprints allows us to explore the neural maturation effects on grammar and word learning. DISCUSSION: This will be one of the largest neuroimaging studies to date that investigates the developmental shift in L2 learning covering preadolescence to adulthood. Our comprehensive approach of combining behavioral and neuroimaging data will contribute to the understanding of the mechanisms influencing this developmental shift and individual differences in new language learning. We aim to answer: (I) do these fingerprints differ according to age and can these explain the age-related differences observed in new language learning? And (II) which aspects of the behavioral and neural fingerprints explain individual differences (across and within ages) in grammar and word learning? The results of this study provide a unique opportunity to understand how the development of brain structure and function influence new language learning success.


Subject(s)
Individuality , Language , Adolescent , Adult , Brain/diagnostic imaging , Child , Cross-Sectional Studies , Humans , Magnetic Resonance Imaging/methods , Neuroimaging , Young Adult
5.
Br Dent J ; 224(2): 59, 2018 01 26.
Article in English | MEDLINE | ID: mdl-29372698
6.
7.
Br Dent J ; 221(11): 696, 2016 12 09.
Article in English | MEDLINE | ID: mdl-27932831
8.
Br J Pharmacol ; 172(10): 2588-603, 2015 May.
Article in English | MEDLINE | ID: mdl-25586266

ABSTRACT

BACKGROUND AND PURPOSE: Asthma exacerbations contribute to corticosteroid insensitivity. LPS is ubiquitous in the environment. It causes bronchoconstriction and airway inflammation and may therefore exacerbate allergen responses. This study examined whether LPS and ovalbumin co-administration could exacerbate the airway inflammatory and functional responses to ovalbumin in conscious guinea pigs and whether these exacerbated responses were insensitive to inhaled corticosteroid treatment with fluticasone propionate (FP). EXPERIMENTAL APPROACH: Guinea pigs were sensitized and challenged with ovalbumin and airway function recorded as specific airway conductance by whole body plethysmography. Airway inflammation was measured from lung histology and bronchoalveolar lavage. Airway hyper-reactivity (AHR) to inhaled histamine was examined 24 h after ovalbumin. LPS was inhaled alone or 24 or 48 h before ovalbumin and combined with ovalbumin. FP (0.05-1 mg·mL(-1) ) or vehicle was nebulized for 15 min twice daily for 6 days before ovalbumin or LPS exposure. KEY RESULTS: Ovalbumin inhalation caused early (EAR) and late asthmatic response (LAR), airway hyper-reactivity to histamine and influx of inflammatory cells into the lungs. LPS 48 h before and co-administered with ovalbumin exacerbated the response with increased length of the EAR, prolonged response to histamine and elevated inflammatory cells. FP 0.5 and 1 mg·mL(-1) reduced the LAR, AHR and cell influx with ovalbumin alone, but was ineffective when guinea pigs were exposed to LPS before and with ovalbumin. CONCLUSIONS AND IMPLICATIONS: LPS exposure exacerbates airway inflammatory and functional responses to allergen inhalation and decreases corticosteroid sensitivity. Its widespread presence in the environment could contribute to asthma exacerbations and corticosteroid insensitivity in humans.


Subject(s)
Asthma/drug therapy , Fluticasone/administration & dosage , Fluticasone/pharmacology , Inflammation/drug therapy , Lipopolysaccharides/adverse effects , Lipopolysaccharides/immunology , Ovalbumin/immunology , Administration, Inhalation , Animals , Asthma/chemically induced , Asthma/immunology , Bronchial Hyperreactivity/chemically induced , Bronchial Hyperreactivity/drug therapy , Bronchoalveolar Lavage Fluid/cytology , Disease Models, Animal , Drug Resistance/drug effects , Fluticasone/therapeutic use , Guinea Pigs , Histamine/adverse effects , Inflammation/chemically induced , Lung/drug effects , Lung/pathology , Male , Plethysmography, Whole Body
10.
Br J Pharmacol ; 167(3): 515-26, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22563753

ABSTRACT

BACKGROUND AND PURPOSE: Inhaled corticosteroids, anticholinergics and ß2-adrenoceptor agonists are frequently combined for treating chronic respiratory diseases. We examine the corticosteroid, budesonide, and novel NO-donating derivative, TPI 1020, against histamine- and methacholine-induced bronchoconstriction and whether they enhance the ß2-adrenoceptor agonist formoterol or muscarinic antagonist tiotropium in conscious guinea pigs. EXPERIMENTAL APPROACH: Dunkin-Hartley guinea pigs received inhaled histamine (3 mM) or methacholine (1.5 mM) and specific airway conductance (sG(aw)) was measured before and 15 or 75 min after treatment with budesonide, TPI 1020, tiotropium or formoterol alone or in combinations. KEY RESULTS: Formoterol (0.7-10 µM) and budesonide (0.11-0.7 mM) inhibited histamine-induced bronchoconstriction and tiotropium (2-20 µM) inhibited methacholine-induced bronchoconstriction by up to 70.8 ± 16.6%, 34.9 ± 4.4% and 85.1 ± 14.3%, respectively. Formoterol (2.5 µM) or tiotropium (2 µM) alone exerted small non-significant bronchoprotection. However, when co-administered with TPI 1020 0.11 mM, which alone had no significant effect, there was significant inhibition of the bronchoconstriction (45.7 ± 12.2% and 79.7 ± 21.4%, respectively). Co-administering budesonide (0.11 mM) with tiotropium (2 µM), which alone had no effect, also significantly inhibited the methacholine bronchoconstriction (36.5 ± 13.0%), but there was no potentiation of formoterol against histamine. The NO scavenger, CPTIO, prevented the bronchoprotection by SNAPand TPI 1020. CONCLUSIONS AND IMPLICATIONS: TPI 1020 potentiated the bronchoprotection by formoterol and tiotropium. Budesonide also enhanced the effects of tiotropium but not formoterol. Combination of TPI 1020 with a long-acting ß2-adrenoceptor agonist or muscarinic receptor antagonist may therefore be a more potent therapeutic approach for treatment of chronic respiratory diseases.


Subject(s)
Bronchodilator Agents/pharmacology , Budesonide/analogs & derivatives , Ethanolamines/pharmacology , Scopolamine Derivatives/pharmacology , Administration, Inhalation , Animals , Bronchoconstriction/drug effects , Bronchodilator Agents/administration & dosage , Budesonide/administration & dosage , Budesonide/pharmacology , Disease Models, Animal , Dose-Response Relationship, Drug , Drug Synergism , Drug Therapy, Combination , Ethanolamines/administration & dosage , Formoterol Fumarate , Guinea Pigs , Histamine/pharmacology , Male , Methacholine Chloride/pharmacology , Respiratory Tract Diseases/drug therapy , Respiratory Tract Diseases/physiopathology , Scopolamine Derivatives/administration & dosage , Time Factors , Tiotropium Bromide
11.
Br Dent J ; 208(10): 449-50, 2010 May 22.
Article in English | MEDLINE | ID: mdl-20489764

ABSTRACT

It is suggested that it makes sense for dentists providing care for individual patients to take account of caries risk (as assessed by presentation of active, non-cavitated lesions) when deciding how to allocate time and effort of themselves and their staff. However, there is a question as to how realistic it is to ask the dental team to provide a full diagnostic assessment and all the preventive treatment required for a patient for the payment provided by 1 UDA. It is to be hoped that one or more of the Steele pilots will come up with a practical solution for controlling caries in NHS practice.


Subject(s)
Cariostatic Agents/administration & dosage , Cariostatic Agents/economics , Dental Caries/prevention & control , Fluorides, Topical/administration & dosage , Fluorides, Topical/economics , General Practice, Dental/economics , State Dentistry/economics , Child , Cost-Benefit Analysis , Dental Caries/economics , Fee Schedules , Humans , United Kingdom
12.
Br J Pharmacol ; 156(7): 1124-35, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19226284

ABSTRACT

BACKGROUND AND PURPOSE: The expression and function of P2X(7) receptors in osteoclasts is well established, but less is known about their role in osteoblast-like cells. A study in P2X(7) receptor knockout mice suggested the involvement of these receptors in bone formation. We have investigated the expression and pharmacology of several P2X receptors in two human osteosarcoma cell lines to see if they could be involved in bone turnover in man. EXPERIMENTAL APPROACH: Reverse transcriptase-polymerase chain reaction and Western blotting were used to study P2X(2), P2X(4) and P2X(7) receptor expression at mRNA and protein levels, respectively, in human osteoblast-like cells. P2X(7) receptor pharmacology was studied by measuring pore formation in the presence of different agonists and antagonists using the YO-PRO 1 uptake method. KEY RESULTS: P2X(4) and P2X(7) receptor mRNA and protein were found to be expressed by these cell lines. No evidence was found for P2X(4)/P2X(7) receptor heteropolymerization. 2'-3'-O-(4-benzoylbenzoyl)adenosine 5'-triphosphate (DBzATP) was equipotent to ATP and the antagonists used were either ineffective or weakly blocked pore formation. CONCLUSIONS AND IMPLICATIONS: This study demonstrates that P2X(4) and P2X(7) receptors are expressed by human osteoblast-like cells. The affinities of the different agonists suggest that the P2X(7) receptor is mainly responsible for pore formation although P2X(4) receptors may also be involved. The low affinity of DBzATP and the weak action of the antagonists support the previously described atypical pharmacology of the P2X(7) receptor in osteoblasts. Targeting the P2X(7) receptor in osteoblasts could represent a promising new treatment for bone diseases such as osteoporosis and rheumatoid arthritis.


Subject(s)
Osteoblasts/metabolism , Purinergic P2 Receptor Agonists , Purinergic P2 Receptor Antagonists , Adenosine Triphosphate/analogs & derivatives , Adenosine Triphosphate/pharmacology , Cell Line , Cell Membrane/drug effects , Cell Membrane/ultrastructure , Glycolysis , Humans , Immunohistochemistry , Immunoprecipitation , Ivermectin/pharmacology , Porosity , Protein Multimerization , RNA, Messenger/biosynthesis , Receptors, Purinergic P2/biosynthesis , Receptors, Purinergic P2X4 , Receptors, Purinergic P2X7 , Reverse Transcriptase Polymerase Chain Reaction
13.
Pattern Recognit ; 42(6): 1162-1171, 2009 Jun 01.
Article in English | MEDLINE | ID: mdl-20161266

ABSTRACT

Accumulating evidence suggests that characteristics of pre-treatment FDG-PET could be used as prognostic factors to predict outcomes in different cancer sites. Current risk analyses are limited to visual assessment or direct uptake value measurements. We are investigating intensity-volume histogram metrics and shape and texture features extracted from PET images to predict patient's response to treatment. These approaches were demonstrated using datasets from cervix and head and neck cancers, where AUC of 0.76 and 1.0 were achieved, respectively. The preliminary results suggest that the proposed approaches could potentially provide better tools and discriminant power for utilizing functional imaging in clinical prognosis.

14.
Br J Pharmacol ; 155(4): 525-34, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18604230

ABSTRACT

BACKGROUND AND PURPOSE: The dietary trace amines tyramine and beta-phenylethylamine (beta-PEA) can increase blood pressure. However, the mechanisms involved in the vascular effect of trace amines have not been fully established. The purpose of this study was to evaluate whether trace amine-dependent vasoconstriction was brought about by tyramine and beta-PEA acting as indirect sympathomimetic agents, as previously assumed, or whether trace amine-dependent vasoconstriction could be mediated by recently discovered trace amine-associated (TAA) receptors. EXPERIMENTAL APPROACH: The responses to p-tyramine and beta-PEA were investigated in vitro in rings of the left anterior descending coronary arteries of pigs. KEY RESULTS: p-Tyramine induced a concentration-dependent (0.1-3 mM) vasoconstriction. The maximum response and pD(2) value for p-tyramine was unaffected by endothelium removal or pre-treatment with antagonists for adrenoceptors, histamine, dopamine or 5-HT receptors. beta-PEA also produced a concentration-dependent (0.3-10 mM) vasoconstriction which was unaffected by endothelium removal, beta-adrenoceptor or 5-HT receptor antagonists. A substantial, but reduced, response to beta-PEA was obtained in the presence of prazosin (alpha(1)-adrenoceptor antagonist), haloperidol (D(2)/D(3) dopamine receptor antagonist) or mepyramine (H(1) histamine receptor antagonist). The pD(2) value for beta-PEA was unaffected by any of the antagonists tested. CONCLUSIONS AND IMPLICATIONS: Vasoconstriction induced by p-tyramine does not involve an indirect sympathomimetic effect, although vasoconstriction caused by beta-PEA may occur, in part, by this mechanism. We therefore propose that trace amine-dependent vasoconstriction is mediated by phenylethylamine-specific receptors, which are closely related to or identical to TAA receptors. These receptors could provide a target for new antihypertensive therapies.


Subject(s)
Phenethylamines/pharmacology , Sympathomimetics/pharmacology , Tyramine/pharmacology , Vasoconstriction/drug effects , Animals , Biogenic Amines/administration & dosage , Biogenic Amines/pharmacology , Coronary Vessels/drug effects , Coronary Vessels/metabolism , Dose-Response Relationship, Drug , Female , In Vitro Techniques , Male , Phenethylamines/administration & dosage , Receptors, Biogenic Amine/drug effects , Receptors, Biogenic Amine/metabolism , Swine , Sympathomimetics/administration & dosage , Tyramine/administration & dosage
15.
Cochrane Database Syst Rev ; (3): CD003808, 2006 Jul 19.
Article in English | MEDLINE | ID: mdl-16856019

ABSTRACT

BACKGROUND: The treatment of deep dental decay has traditionally involved removal of all the soft demineralised dentine before a filling is placed. However this has been challenged in three groups of studies which involve sealing soft caries into the tooth. The three main groups either remove no caries and seal the decay into the tooth, remove minimal (ultraconservative) caries at the entrance to a cavity and seal the remaining caries in, or remove caries in stages over two visits some months apart to allow the pulp time to lay down reparative dentine (the stepwise excavation technique). OBJECTIVES: To test the null hypothesis of no difference in the incidence of damage or disease of the nerve of the tooth (pulp), progression of decay and longevity of restorations irrespective of whether the removal of decay had been minimal (ultraconservative) or complete. SEARCH STRATEGY: The Cochrane Oral Health Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PubMed and EMBASE databases were searched. The reference lists in relevant papers were checked. SELECTION CRITERIA: Randomised controlled trials and controlled clinical trials comparing minimal (ultraconservative) caries removal with complete caries removal in unrestored permanent and deciduous teeth. DATA COLLECTION AND ANALYSIS: Outcome measures recorded were exposure of the nerve of the tooth (pulp) during caries removal, patient experience of symptoms of pulpal inflammation or necrosis, progression of caries under the filling, time until the filling was lost or replaced. Due to the heterogeneity of the included studies the overall estimate of effect was calculated using a random-effects model. MAIN RESULTS: Four studies met the inclusion criteria; two stepwise excavation studies and two ultraconservative caries removal studies. Partial caries removal in symptomless, primary or permanent teeth reduces the risk of pulp exposure. We found no detriment to the patient in terms of pulpal symptoms in this procedure and no reported premature loss or deterioration of the restoration. AUTHORS' CONCLUSIONS: The results of this systematic review reject the null hypothesis of no difference in the incidence of damage or disease of the nerve of the tooth (pulp) irrespective of whether the removal of decay had been minimal (ultraconservative) or complete and accepts the null hypothesis of no difference in the progression of decay and longevity of restorations. However, the number of included studies is small and differ considerably. Partial caries removal is therefore preferable to complete caries removal in the deep lesion, in order to reduce the risk of carious exposure. However, there is insufficient evidence to know whether it is necessary to re-enter and excavate further but studies that have not re-entered do not report adverse consequences.


Subject(s)
Cariostatic Agents/therapeutic use , Dental Caries/therapy , Dental Pulp , Pit and Fissure Sealants/therapeutic use , Dental Caries/drug therapy , Dental Enamel/drug effects , Dental Enamel/surgery , Dental Restoration, Permanent/methods , Humans , Randomized Controlled Trials as Topic
16.
Auton Autacoid Pharmacol ; 26(2): 191-200, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16553647

ABSTRACT

The binding and functional properties of adenosine receptor ligands were compared in Chinese hamster ovary cells transfected with human adenosine A(3) receptors. Inhibition of [(125)I]-aminobenzyl-5'-N-methylcarboamidoadenosine ([(125)I]-AB-MECA) binding by adenosine receptor ligands was examined in membrane preparations. Inhibition of forskolin-induced cAMP accumulation by agonists was measured using a cAMP enzyme immunoassay. The rank order of agonist potency for both assays was N(6)-(3-iodobenzyl)-adenosine-5'-N-methyluronamide (IB-MECA) > 5'-N-ethylcarboxamidoadenosine (NECA) > (-)-N(6)-[(R)-phenylisopropyl] adenosine (R-PIA) > 4-aminobenzyl-5'-N-methylcarboxamidoadenosine (AB-MECA) > N(6)-cyclopentyl adenosine (CPA) > adenosine. The radioligand binding rank order of antagonist potency was N-[9-chloro-2-(2-furanyl)[1,2,4]-triazolo[1,5-c]quinazolin-5-benzeneacetamide (MRS1220) > 1,3-dipropyl-8-cyclopentylxanthine (DPCPX) > 8-phenyltheophylline (8-PT) > 8-(p-sulfophenyl)-theophylline (8-SPT). MRS1220 competitively inhibited the effect of IB-MECA on cAMP production, with a K(B) value of 0.35 nm. These data are characteristic of adenosine A(3) receptors. The absence of Mg(2+) and presence of guanosine 5'-(gamma-thio)triphosphate (GTPgammaS) significantly reduced agonist binding inhibition potency, indicating binding to high- and low-affinity states. The IB-MECA, NECA and R-PIA IC(50) values were greater for the cAMP assay than for radioligand binding, suggesting an efficient stimulus-response transduction pathway.


Subject(s)
Adenosine/analogs & derivatives , Radioligand Assay , Receptor, Adenosine A3/metabolism , Adenosine/pharmacology , Animals , Binding, Competitive , CHO Cells , Cricetinae , Cyclic AMP/biosynthesis , Cyclic AMP/metabolism , Guanosine 5'-O-(3-Thiotriphosphate)/pharmacology , Iodine Radioisotopes , Ligands , Magnesium Chloride , Quinazolines/pharmacology , Receptor, Adenosine A3/analysis , Receptor, Adenosine A3/drug effects , Recombinant Proteins/metabolism , Transfection , Triazoles/pharmacology
17.
Br Dent J ; 199(8): 485, 2005 Oct 22.
Article in English | MEDLINE | ID: mdl-16244599
18.
Caries Res ; 39(3): 231-5, 2005.
Article in English | MEDLINE | ID: mdl-15914986

ABSTRACT

To compare the effects of fluoride-containing and fluoride-free toothpaste on plaque microflora, 15 subjects were enrolled in a double-blind crossover trial. All subjects used a fluoride toothpaste for 7 days before the trial started. Then, 4 interproximal sites per subject were professionally cleaned and subjects used one of the toothpastes for 5 days. On the 5th day plaque was collected from 2 sites, 12 and 6 h after toothpaste use. There was no difference between the groups in the numbers or proportions of aciduric bacteria (recovered at pH 4.8 or 5.2), or of yeasts, neisseriae, lactobacilli or streptococci (total or individual species, including Streptococcus mutans). However, the numbers and proportions of Gram-positive pleomorphic rods, primarily Actinomyces naeslundii, increased in 6-hour samples from subjects using fluoride toothpaste. The data suggest that the anti-caries effect of fluoride toothpaste is not mediated primarily through effects on the plaque microflora, although effects on plaque physiology could be important.


Subject(s)
Cariostatic Agents/therapeutic use , Dental Plaque/microbiology , Fluorides/therapeutic use , Toothpastes/chemistry , Adult , Cross-Over Studies , Dental Plaque/drug therapy , Double-Blind Method , Humans , Middle Aged , Statistics, Nonparametric , Toothpastes/therapeutic use
19.
Appl Environ Microbiol ; 71(5): 2467-72, 2005 May.
Article in English | MEDLINE | ID: mdl-15870335

ABSTRACT

The effects of sealing infected carious dentine below dental restorations on the phenotypic and genotypic diversity of the surviving microbiota was investigated. It was hypothesized that the microbiota would be subject to nutrient limitation or nutrient simplification, as it would no longer have access to dietary components or salivary secretion for growth. The available nutrients would be limited primarily to serum proteins passing from the pulp through the patent dentinal tubules to the infected dentine. Ten lesions were treated, and infected dentine was sealed below dental restorations for approximately 5 months. Duplicate standardized samples of infected dentine were taken at baseline and after the removal of the restorations. The baseline microbiota were composed primarily of Lactobacillus spp., Streptococcus mutans, Streptococcus parasanguinis, Actinomyces israelii, and Actinomyces gerencseriae. None of these taxa were isolated among the microbiota of the dentine samples taken after 5 months, which consisted of only Actinomyces naeslundii, Streptococcus oralis, Streptococcus intermedius, and Streptococcus mitis. The microbiota of the final sample exhibited a significantly (P < 0.001) increased ability to produce glycosidic enzymes (sialidase, beta-N-acetylglucosaminidase, and beta-galactosidase), which liberate sugars from glycoproteins. The genotypic diversity of S. oralis and A. naeslundii was significantly (P = 0.002 and P = 0.001, respectively) reduced in the final samples. There was significantly (P < 0.001) greater genotypic diversity within these taxa between the pairs of dentine samples taken at baseline than was found in the 5-month samples, indicating that the dentine was more homogenous than it was at baseline. We propose that during the interval between placement of the restorations and their removal, the available nutrient, primarily serum proteins, or the relative simplicity and homogeneity of the nutrient supply significantly affected the surviving microbiota. The surviving microbiota was less complex, based on compositional, phenotypic, and genotypic analyses, than that isolated from carious lesions which were also exposed to salivary secretions and pH perturbations.


Subject(s)
Colony Count, Microbial , Dental Cavity Preparation , Dentin/microbiology , Acetylglucosaminidase/metabolism , Biofilms , Genotype , Humans , Hydrogen-Ion Concentration , Neuraminidase/metabolism , Phenotype , beta-Galactosidase/metabolism
20.
Caries Res ; 39(1): 78-84, 2005.
Article in English | MEDLINE | ID: mdl-15591739

ABSTRACT

The relationship between microflora, eruption status and caries status in the first permanent molar of young children was investigated in 177 children aged 6-7 years. A significantly greater proportion of fully erupted teeth were classified as sound and plaque-free compared to partially erupted teeth. Fully erupted teeth yielded greater numbers and proportions of mutans streptococci compared with significantly greater numbers and proportions of Actinomyces israelii in partially erupted teeth. Logistical regression analysis showed significant associations between white spot lesions in partially erupted teeth and increased numbers of Streptococcus oralis, mutans streptococci and Streptococcus salivarius whereas the presence of Actinomyces naeslundii was associated with health. Significantly greater numbers and proportions of S. oralis and S. salivarius were isolated from partially erupted teeth with white spot lesions whereas Streptococcus mutans was isolated in significantly greater numbers and proportions from fully erupted molars with white spots. This study suggests that organisms other than mutans streptococci are associated with caries development in erupting permanent molar teeth.


Subject(s)
Dental Plaque/microbiology , Molar/microbiology , Tooth Eruption , Actinomyces/isolation & purification , Child , Colony Count, Microbial , Dentition, Permanent , Humans , Logistic Models , Streptococcus/isolation & purification
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