RÉSUMÉ
In recent years, several forensic laboratories have noted an increase in the number of sexual assault cases submitted for testing, often leading to longer turnaround times. In that context, forensic laboratories may be interested in reviewing their procedures to increase productivity. Here, we present two different strategies that were put in place in our laboratory. First, we changed the way sexual assault evidence kits (SAEK) are processed by implementing an optimized workflow that prioritizes the internal samples (vaginal, anal, and oral). This new procedure allowed for a drastic decrease in turnaround time, while maintaining a similar investigative power. Secondly, we used data from casework to target cases and samples that were likely to yield biological material from the perpetrator, in an attempt to avoid dedicating time and effort to cases for which there is a very low probability of obtaining foreign DNA evidence. Among other things, we looked at the likelihood of obtaining DNA from the perpetrator when the complainant reported the use of a condom, has showered after the assault or when the complainant has no memory of the assault. Results show that those circumstances do not dramatically decrease the probability of finding DNA from the perpetrator.
RÉSUMÉ
Persistent postoperative pain is a very common phenomenon which severely affects the lives of patients who develop it following common surgical procedures. Opioid analgesics are of limited efficacy in the treatment of persistent pain states because of side effects including antinociceptive tolerance. We have previously shown that surgical incision injury and morphine tolerance share similar mechanisms, including a CNS role of spinal cord glia. We therefore hypothesized that prior chronic morphine exposure would inhibit the resolution of postoperative allodynia through increased glial ionized calcium-binding adaptor protein 1 (Iba1) and glial fibrillary acidic protein (GFAP) protein expression and mitogen activated protein kinase (MAPK) activation. To test this hypothesis, rats were implanted with s.c. osmotic minipumps on day zero, releasing saline or morphine for 7 days preceding or 7 days preceding and following paw incision surgery, which was completed on day seven. Thermal hyperalgesia and mechanical allodynia were assessed postoperatively every 3 days. Chronic morphine attenuated the resolution of postoperative thermal hyperalgesia and mechanical allodynia through day 20. However, no changes in Iba1 or GFAP expression were observed in the spinal cord dorsal horn between groups. Assessment of MAPK protein phosphorylation revealed that chronic morphine administration enhanced both p38 and extracellular receptor kinase (pERK) phosphorylation compared to saline on day 20. p-p38 and pERK immunofluorescence were only observed to colocalize with a marker of microglial cells and not with markers of astrocytes or neurons. Together, these data demonstrate that chronic morphine administration attenuates the resolution of postoperative allodynia in association with microglial p38 and extracellular receptor kinase (ERK) phosphorylation, independent of changes in Iba1 and GFAP expression.
Sujet(s)
Extracellular Signal-Regulated MAP Kinases/métabolisme , Morphine/pharmacologie , Stupéfiants/pharmacologie , Douleur postopératoire/physiopathologie , Moelle spinale/effets des médicaments et des substances chimiques , p38 Mitogen-Activated Protein Kinases/métabolisme , Animaux , Protéines de liaison au calcium/biosynthèse , Tolérance aux médicaments , Protéine gliofibrillaire acide/biosynthèse , Température élevée , Mâle , Protéines des microfilaments , Mesure de la douleur , Douleur postopératoire/métabolisme , Phosphorylation , Rats , Rat Sprague-Dawley , Moelle spinale/métabolisme , ToucherRÉSUMÉ
OBJECTIVE: To develop a test method for characterizing glare from intraocular lenses (IOLs) and to confirm a clinical finding that the haptic insertion in the optic of a three-piece IOL produces extraneous line images. METHOD: The method consists of directing a collimated Gaussian laser beam to various parts of the IOL to be tested in a water-filled model eye. Reflected images produced in the retinal plane are photographed with a digital camera. RESULTS: A test method was developed to characterize the source of glare images from IOLs. The test method developed was used to confirm a clinical finding that the haptic insertion in the optic of a three-piece IOL produces extraneous line images. CONCLUSIONS: The method developed can be used to characterize and pin point the source of extraneous glare images from intraocular lens implants. The haptic insertion in the optic of a three-piece IOL has been identified as a source of line images.
Sujet(s)
Lumière éblouissante , Pose d'implant intraoculaire/effets indésirables , Lentilles intraoculaires/effets indésirables , Femelle , Humains , Thérapie laser/méthodes , Pose d'implant intraoculaire/méthodes , Mâle , Modèles biologiques , Réfraction oculaireRÉSUMÉ
OBJECTIVE: To identify the source of unwanted glare images from a three-piece intraocular lens (IOL) implant following cataract surgery. METHOD: The IOL and posterior capsule were examined under mydriatic and nonmydriatic conditions using direct focal illumination from a slit lamp biomicroscope. Direct focal illumination was undertaken with both a narrow beam (0.1 mm in width) and small spot (0.1 mm in diameter) to identify the points at which the glare images were stimulated. While observing the location of the beam with the slit lamp biomicroscope, the patient indicated when the glare images were stimulated. RESULTS: The nasal haptic insertion into the optic was identified as the source of temporal line images arising from lights such as headlamps from oncoming cars and street lamps. The adjacent edge of the IOL was also identified as the likely source of additional cob web-like light rays. CONCLUSIONS: The haptic insertions in three-piece IOLs may, under certain conditions, interfere with light entering the pupil and produce extraneous images. Large mesopic pupils and decentred IOLs are conditions that increase the likelihood of unwanted glare images.
Sujet(s)
Lumière éblouissante , Pose d'implant intraoculaire/effets indésirables , Lentilles intraoculaires , Acuité visuelle , Sujet âgé , Extraction de cataracte , Humains , Mâle , Conception de prothèse , Résultat thérapeutiqueRÉSUMÉ
A stylized, symmetric, compartmental model of a dopamine neuron in vivo shows how rate and pattern can be modulated either concurrently or differentially. If two or more parameters in the model are varied concurrently, the baseline firing rate and the extent of bursting become de-correlated, which provides an explanation for the lack of a tight correlation in vivo and is consistent with some independence of the mechanisms that generate baseline firing rates versus bursts. We hypothesize that most bursts are triggered by a barrage of synaptic input and that particularly meaningful stimuli recruit larger numbers of synapses in a more synchronous way. An example of concurrent modulation is that increasing the short-lived AMPA current evokes additional spikes without regard to pattern, producing comparable increases in spike frequency and fraction fired in bursts. On the other hand, blocking the SK current evokes additional bursts by allowing a depolarization that previously produced only a single spike to elicit two or more and elongates existing bursts by the same principle, resulting in a greater effect on pattern than rate. A probabilistic algorithm for the random insertion of spikes into the firing pattern produces a good approximation to the pattern changes induced by increasing the AMPA conductance, but not by blocking the SK current, consistent with a differential modulation in the latter case. Furthermore, blocking SK produced a longer burst with a greater intra-burst frequency in response to a simulated meaningful input, suggesting that reduction of this current may augment reward-related responses.
Sujet(s)
Dopamine/physiologie , Modèles neurologiques , Neurones/physiologie , Récepteur de l'AMPA/physiologie , Canaux potassiques calcium-dépendants de petite conductance/physiologie , Algorithmes , Dendrites/physiologie , Électrophysiologie , Potentiels post-synaptiques excitateurs/physiologie , Espace extracellulaire/physiologie , Glutamates/physiologie , Canaux ioniques/physiologie , Potentiels de membrane/physiologie , Modèles statistiques , Récepteurs du N-méthyl-D-aspartate/physiologie , Acide gamma-amino-butyrique/physiologieRÉSUMÉ
AIMS: Six Canadian dental schools investigated the ability of a thermosetting gel containing 25 mg/g prilocaine and 25 mg/g lidocaine as active agents to produce analgesia in periodontal pockets utilizing a randomized, double-blind, placebo-controlled study. MATERIALS AND METHODS: The study consisted of 130 patients, each of whom received the active or placebo gel in periodontal pockets in one quadrant of the mouth for 30 s prior to periodontal debridement (scaling and root planing). Pain was measured using both a 100-mm Visual Analogue Scale (VAS) and a Verbal Rating Scale (VRS). RESULTS: The median VAS pain score for the patients treated with the anaesthetic gel was 5 mm (range 0-85 mm) as opposed to 13 mm (range 0-79 mm) in the placebo-treated patients (P=0.015). There was no significant difference in the percentage of patients reporting no or mild pain (78% and 76% for the anaesthetic gel and placebo, respectively). No significant differences were seen in patient demographics, or mandible versus maxilla. CONCLUSIONS: The VAS pain scores showed that the anaesthetic gel 5% was statistically more effective than the placebo in reducing pain during periodontal debridement.
Sujet(s)
Anesthésiques combinés/administration et posologie , Anesthésiques locaux/administration et posologie , Lidocaïne/administration et posologie , Poche parodontale/thérapie , Prilocaïne/administration et posologie , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Intervalles de confiance , Détartrage dentaire , Méthode en double aveugle , Gels , Humains , Association de lidocaïne et de prilocaïne , Mandibule , Maxillaire , Adulte d'âge moyen , Mesure de la douleur , Placebo , Surfaçage radiculaire , Statistique non paramétrique , Facteurs tempsRÉSUMÉ
Periodontal disease is a widespread condition ranging from simple gingival inflammation to severe periodontal breakdown. Early detection and diagnosis are key elements in the prevention of this oral pathology. Diagnostic aids available to dentists, such as the Periodontal Screening and Recording or PSR Index, accelerate the screening of periodontal conditions. While many studies provide support for the PSR Index as a valuable tool because it is reproducible, reliable, and quick, others have suggested that it may under or overestimate existing periodontal conditions. Some authors have suggested modifications to the recording method to improve its use either for screening purposes or for monitoring the outcome of periodontal therapy. This literature review briefly describes the PSR method, and compares studies based on both PSR and its counterpart, CPITN, in order to evaluate its usefulness and establish its limitations in a clinical setting.
Sujet(s)
Maladies parodontales/diagnostic , Indice parodontal , Évolution de la maladie , Besoins et demandes de services de santé , Humains , Dépistage de masse , Maladies parodontales/classification , Maladies parodontales/épidémiologieRÉSUMÉ
Heparan sulfate proteoglycans are found on the surface of most cells. Syndecan-4 is a widely expressed transmembrane heparan sulfate proteoglycan. Using quantitative RNase protection assays and immunoblotting, syndecan-4 expression was characterized in 3T3-F442A mouse adipoblasts. These cells exhibit dramatic changes in their biological and morphological characteristics during differentiation to adipocytes. During this process, the levels of syndecan-4 protein and mRNA expression changed dramatically. They peaked at the time when quiescent cells reentered the cell cycle before differentiation. Serum depletion-repletion also replicated the syndecan-4 mRNA induction when the cells were released back into proliferation, and a cycloheximide treatment abolished the peak of induction. In addition, inhibiting syndecan-4 induction with antisense oligonucleotides inhibited the proliferation of 3T3-F442A cells. In the terminally differentiated adipocytes characterized by the loss of proliferation capability, the serum inducibility of syndecan-4 is repressed, emphasizing the link between syndecan-4 induction in 3T3-F442A cells and cell proliferation.
Sujet(s)
Adipocytes/métabolisme , Glycoprotéines membranaires/biosynthèse , Protéoglycanes/biosynthèse , Cellules 3T3 , Animaux , Division cellulaire , Lignée cellulaire , ADN complémentaire/métabolisme , Relation dose-effet des médicaments , Immunotransfert , Souris , Oligonucléotides antisens/pharmacologie , ARN messager/métabolisme , Ribonucléases/métabolisme , Syndécane-4 , Facteurs tempsRÉSUMÉ
Epitope mapping studies and the determination of the structure to 1.8 A resolution have been carried out for the antigen-binding fragment MR1 in complex with peptide antigen. MR1 is specific for the novel fusion junction of the mutant epidermal growth factor receptor EGFRvIII and has been reported to have a high degree of specificity for the mutant EGFRvIII over the wild-type EGF receptor. The structure of the complex shows that the peptide antigen residue side-chains found by epitope mapping studies to be critical for recognition are accommodated in pockets on the surface of the Fv. However, the most distinctive portion of the peptide antigen, the novel fusion glycine residue, makes no contact to the Fv and does not contribute directly to the epitope. The specificity of MR1 lies in the ability of this glycine residue to assume the restricted conformation needed to form a type II' beta-hairpin turn more easily, and demonstrates that a peptide antigen can be used to generate a conformational epitope.
Sujet(s)
ADP ribose transferases , Spécificité des anticorps , Toxines bactériennes , Cartographie épitopique , Épitopes/composition chimique , Récepteurs ErbB/composition chimique , Récepteurs ErbB/immunologie , Fragments d'immunoglobuline/composition chimique , Fragments d'immunoglobuline/immunologie , Facteurs de virulence , Séquence d'acides aminés , Antigènes/composition chimique , Antigènes/immunologie , Séquence nucléotidique , Cristallographie aux rayons X , Disulfures/métabolisme , Test ELISA , Épitopes/immunologie , Récepteurs ErbB/génétique , Exotoxines/composition chimique , Exotoxines/génétique , Exotoxines/métabolisme , Liaison hydrogène , Fragments d'immunoglobuline/génétique , Modèles moléculaires , Données de séquences moléculaires , Mutation/génétique , Fragments peptidiques/synthèse chimique , Fragments peptidiques/composition chimique , Fragments peptidiques/immunologie , Conformation des protéines , Ingénierie des protéines , Pseudomonas , Protéines de fusion recombinantes/composition chimique , Protéines de fusion recombinantes/génétique , Protéines de fusion recombinantes/immunologie , Protéines de fusion recombinantes/métabolisme , Température , Thermodynamique ,RÉSUMÉ
BACKGROUND: A double-blind, randomized, parallel, comparative study was designed to evaluate the long-term safety and efficacy of subgingivally administered minocycline ointment versus a vehicle control. METHODS: One hundred four patients (104) with moderate to severe adult periodontitis (34 to 64 years of age; mean 46 years) were enrolled in the study. Following scaling and root planing, patients were randomized to receive either 2% minocycline ointment or a matched vehicle control. Study medication was administered directly into the periodontal pocket with a specially designed, graduated, disposable applicator at baseline; week 2; and at months 1, 3, 6, 9, and 12. Scaling and root planing was repeated at months 6 and 12. Standard clinical variables (including probing depth and attachment level) were evaluated at baseline and at months 1, 3, 6, 9, 12, and 15. Microbiological sampling using DNA probes was done at baseline; at week 2; and at months 1, 3, 6, 9, 12, and 15. RESULTS: Both treatment groups showed significant and clinically relevant reductions in the numbers of each of the 7 microorganisms measured during the entire 15-month study period. When differences were detected, sites treated with minocycline ointment always produced statistically significantly greater reductions than sites which received the vehicle control. For initial pockets > or =5 mm, a mean reduction in probing depth of 1.9 mm was seen in the test sites, versus 1.2 mm in the control sites. Sites with a baseline probing depth > or =7 mm and bleeding index >2 showed an average of 2.5 mm reduction with minocycline versus 1.5 mm with the vehicle. Gains in attachment (0.9 mm and 1.1 mm) were observed in minocycline-treated sites, with baseline probing depth > or =5 mm and > or =7 mm, respectively, compared with 0.5 mm and 0.7 mm gain at control sites. Subgingival administration of minocycline ointment was well tolerated. CONCLUSIONS: Overall, the results demonstrate that repeated subgingival administration of minocycline ointment in the treatment of adult periodontitis is safe and leads to significant adjunctive improvement after subgingival instrumentation in both clinical and microbiologic variables over a 15-month period.
Sujet(s)
Antibactériens/administration et posologie , Minocycline/administration et posologie , Poche parodontale/traitement médicamenteux , Poche parodontale/microbiologie , Parodontite/traitement médicamenteux , Parodontite/microbiologie , Adulte , Aggregatibacter actinomycetemcomitans/effets des médicaments et des substances chimiques , Analyse de variance , Campylobacter/effets des médicaments et des substances chimiques , Canada , Maladie chronique , Numération de colonies microbiennes , Indice de plaque dentaire , Détartrage dentaire , Méthode en double aveugle , Eikenella corrodens/effets des médicaments et des substances chimiques , Europe , Femelle , Fusobacterium nucleatum/effets des médicaments et des substances chimiques , Humains , Études longitudinales , Mâle , Adulte d'âge moyen , Onguents , Indice parodontal , Porphyromonas gingivalis/effets des médicaments et des substances chimiques , Prevotella intermedia/effets des médicaments et des substances chimiques , Statistique non paramétrique , Résultat thérapeutique , Treponema/effets des médicaments et des substances chimiquesRÉSUMÉ
The potential for noninvasive detection of blood glucose is an area of intense academic and commercial research and a subject of keen interest in the diabetic and healthcare communities. A number of techniques are under investigation that attempt to infer blood glucose levels from measurements of optical signals. Frequently, these techniques are based on laser sources that may, under certain circumstances, be capable of inducing ocular injury. This article provides an overview of ocular damage mechanisms and the international standards for laser exposure limits that have been developed. The application of relevant standards to specific implementations of lasers in optical glucose sensing is presented. In addition, the concept of risk versus benefit for consideration of new medical devices is also discussed.
Sujet(s)
Autosurveillance glycémique/instrumentation , Glycémie/analyse , Oeil/effets des radiations , Radioprotection , Animaux , Autosurveillance glycémique/effets indésirables , Autosurveillance glycémique/normes , Humains , LasersRÉSUMÉ
In rural areas, groundwater contamination by nitrates is a problem related to the spreading of organic and chemical fertilizers by farmers and, to some extent, to effluents from domestic sewage systems. Health effects of groundwater contamination by nitrates have been assessed several times and may lead to important consequences for infants. Following pressures from citizens in 1990, a survey of well water quality around potato fields of the Portneuf county (Québec) found that nitrate contamination was frequently above the 10 mg-N/1 standard. Because this first survey was limited to areas of intensive potato culture, it was not possible to evaluate the real impact on the groundwater quality for the whole county and the subsequent public health intervention was spread over the entire region. A second survey was carried out in 1995 to reevaluate the situation using random sampling methods. This latter study took into account drinking water habits of the population, the relative importance of potato culture as a source of nitrogen loading, the effects of soil types, and waste-water disposal systems as well as land use on nitrate concentration in private well water. The data analysis was carried out by combining GIS and statistical methods to test hypotheses about the spatial relationship linking measured nitrate concentrations with their immediate environment. This paper presents the major findings from this second study which confirm the impact of intensive potato culture on groundwater nitrate concentrations, mainly localized in sandy soil areas within 2 km of fields. Finally, it illustrates the usefulness of GIS to focus public health interventions.
Sujet(s)
Agriculture , Surveillance de l'environnement , Nitrates/analyse , Santé publique , Polluants du sol/analyse , Polluants chimiques de l'eau/analyse , Engrais , Humains , Systèmes d'information , Québec , Eaux d'égout , Solanum tuberosum , Alimentation en eau/normesRÉSUMÉ
The period of adolescence is characterized as a time of experimentation during which adolescents may engage in adult behavior in the absence of understanding the consequences of these behaviors. The purpose of this study was to examine the self-reported sexual behaviors of late adolescent junior and senior high school students (N = 7,699). The study indicated a significantly high and disconcerting frequency of self-reported risk-taking sexual behavior.
Sujet(s)
Comportement sexuel , Étudiants/psychologie , Adolescent , Adulte , Femelle , Connaissances, attitudes et pratiques en santé , Humains , Mâle , Dakota du Nord , Grossesse , Grossesse de l'adolescente/psychologie , Grossesse de l'adolescente/statistiques et données numériques , Prise de risque , Révélation de soi , Étudiants/statistiques et données numériquesRÉSUMÉ
Microorganisms can be removed from dental instruments by various methods, including treatment in salt and glass bead sterilizers. However, no rigorous, controlled, in vivo or in vitro studies have been performed to verify the respective efficiencies of these methods. The goals of this study were to determine if the positioning of instruments at the centre or edge of a salt sterilizer results in differential sterilization effectiveness, and to compare the effectiveness of salt sterilizers relative to glass bead sterilizers. Autoclaved number 60 reamers were contaminated by plunging them to the handle in a commercial Bacillus stearothermophilus spore suspension. They were then sterilized for different periods of time and at different positions in the sterilizers. Each experiment included positive and negative controls. The results showed that better sterilization is achieved at the edge of the chamber than at the centre, and that salt sterilizers are more effective than glass bead sterilizers for a given period of time (15 seconds) in the sterilizer.
Sujet(s)
Instruments dentaires , Verre , Chlorure de sodium , Stérilisation/instrumentation , Milieux de culture , Contamination de matériel/prévention et contrôle , Geobacillus stearothermophilus/croissance et développement , Humains , Reproductibilité des résultats , Spores bactériens/croissance et développement , Stérilisation/méthodes , Propriétés de surface , Température , Facteurs tempsRÉSUMÉ
Periodontal disease seems to be more prevalent in smokers than in nonsmokers. Studies have reported both increases and decreases in gingival blood flow due to smoking. Smoking does not increase the presence of the periodontopathogens Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Bacteroides intermedius. Both the chemotaxis and the phagocytic capacity of the polymorphonuclear leukocytes (PMNs) harvested from smokers are lower than with those harvested from nonsmokers. Furthermore, smokers have lower IgA, IgG, IgM, and suppressor CD8 lymphocytes levels than nonsmokers. These differences between smokers and nonsmokers should be taken into account by clinicians during periodontal examinations, therapy, and the healing process.
Sujet(s)
Parodontite/étiologie , Fumer/effets indésirables , Adhérence cellulaire/effets des médicaments et des substances chimiques , Fibroblastes/effets des médicaments et des substances chimiques , Humains , Immunité/effets des médicaments et des substances chimiques , Granulocytes neutrophiles/effets des médicaments et des substances chimiques , Nicotine/effets indésirables , Parodontite/immunologie , Parodonte/vascularisation , Parodonte/immunologie , Phagocytose/effets des médicaments et des substances chimiques , Salivation/effets des médicaments et des substances chimiques , Xérostomie/étiologieRÉSUMÉ
PURPOSE: We report preliminary results of a new procedure for correcting high astigmatism after penetrating keratoplasty. METHODS: The procedure entails full-thickness trephination along the original donor-recipient junction with careful suturing in a combined interrupted and running fashion. Four eyes of four patients with severe astigmatism and myopia after penetrating keratoplasty underwent the procedure. RESULTS: High preoperative cylinder ranging from 4.50 to 16.00 D (mean 9.00 D) was reduced to 0.50 to 3.50 D (mean 1.90 D) at the last examination (between 3 to 6 months). Spherical equivalent myopia ranging from -2.00 to -10.25 D (mean -4.90 D) was essentially unchanged at plano to -9.00 D (-4.70 D) at the last examination. Overall, there was a mean refractive cylinder reduction of 7.10 D (79%). CONCLUSION: Retrephination after penetrating keratoplasty appears to be an acceptable alternative for correcting high astigmatism, and had only a small effect on the level of myopia.
Sujet(s)
Astigmatisme/chirurgie , Cornée/chirurgie , Transplantation de cornée/méthodes , Kératoplastie transfixiante/effets indésirables , Astigmatisme/étiologie , Astigmatisme/physiopathologie , Cornée/physiopathologie , Humains , Traitement d'image par ordinateur , Réintervention , Techniques de suture , Acuité visuelleRÉSUMÉ
Wearing removable dental prosthesis causes an alteration in the oral microflora. For certain individuals, this new environment is responsible for the development of a particular condition: prosthetic stomatitis. This article reviews the pertinent literature regarding the main predisposing factors causing the disease. It targets the different risk groups and identifies the proposed mechanism for the proliferation of Candida albicans on the palatal side of the prosthesis. Various treatments depending on the severity of the disease are also mentioned.
Sujet(s)
Prothèse dentaire complète/effets indésirables , Facteurs âges , Sujet âgé , Antifongiques/usage thérapeutique , Candidose buccale/traitement médicamenteux , Candidose buccale/étiologie , Vernis protecteurs d'appareil de prothèse dentaire , Femelle , Humains , Mâle , Facteurs sexuels , Stomatite prothétique/étiologie , Stomatite prothétique/microbiologie , Stomatite prothétique/thérapie , Mise en condition tissulaire (dentisterie)RÉSUMÉ
Bacteria are the principal causal factor for gingivitis and adult periodontitis. This article is a review of the pertinent literature regarding subgingival irrigation with antimicrobial agents. Furthermore, the clinical significance of this technique is evaluated. In order for the antimicrobial agent to reach the base of the periodontal pocket, the canula must be placed at least 3.0 mm subgingivally. Subgingival irrigation offers no added antimicrobial effect over root scaling alone, but may extend the therapeutic effect of scaling. The effect of subgingival irrigation is none the less temporary. Subgingival irrigation must be regarded as an alternative treatment for gingivitis and adult periodontitis when root scaling alone is not sufficient.
Sujet(s)
Anti-infectieux locaux/usage thérapeutique , Gingivite/traitement médicamenteux , Parodontite/traitement médicamenteux , Adulte , Anti-infectieux locaux/administration et posologie , Bactéries/effets des médicaments et des substances chimiques , Détartrage dentaire , Gingivite/microbiologie , Humains , Poche parodontale/traitement médicamenteux , Poche parodontale/microbiologie , Parodontite/microbiologie , Surfaçage radiculaire , Irrigation thérapeutique/instrumentation , Irrigation thérapeutique/méthodes , Facteurs tempsRÉSUMÉ
BACKGROUND AND OBJECTIVES: Free radicals, detected previously in corneal tissue following 193 nm laser irradiation, may be important agents in the laser/tissue interaction. Electron paramagnetic resonance spectroscopy (EPR) has been used to examine such radical formation in detail. STUDY DESIGN/MATERIALS AND METHODS: Bovine corneal strips were frozen in liquid nitrogen, irradiated with excimer laser pulses, and assayed by EPR. Exposure conditions were varied to study radical formation dependence on laser intensity and repetition. Results were measured against a quantifiable standard to calculate radical quantum yield. RESULTS: Either weak or intense laser fluences produced comparable tissue EPR signals. Radicals accumulated in frozen tissue for at least 10 initial ablation pulses. Radical quantum yield in cornea was 0.15%. CONCLUSION: Corneal radical formation is largely a photochemical process driven by the 193 nm laser radiation. Reactive radical species are produced in substantial numbers and likely have a significant clinical role.