Normal and abnormal mucosal antibody mediated immunity.
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Administration, Oral↗
Biomedical subjects
D Ericson
Publications and source records attributed to D Ericson.
Human leukocyte antigens in relation to colonization by mutans streptococci in the oral cavity.
Mutans streptococci are well established as caries-inducing microorganisms in man. Most humans carry the bacteria, but in highly different numbers. This cannot be explained by environmental factors only. The aim of this study was to investigate a possible association between levels of colonization by mutans streptococci and the presence of certain B and DR human leukocyte antigens (HLA). Altogether, 170 subjects who had their HLA antigens determined (76 renal transplant patients and 94 healthy blood donors) were selected for the investigation. Paraffin-stimulated saliva samples were taken using the wooden spatula method with subsequent cultivation of mutans streptococci on mitis salivarius bacitracin agar plates. An association between the absence of HLA-DR 4 antigens and low, or undetectable, levels of mutans streptococci was found. This was statistically significant for the immunosuppressed renal transplant subjects. The same trend was observed among the healthy blood donors.
Adult↗
In vitro antibacterial effect of chlorhexidine added to glass-ionomer cements.
The aims of the present study were to investigate the antibacterial properties of glass-ionomer cements containing different concentrations of chlorhexidine and the possible release of chlorhexidine from the compound. Chlorhexidine gluconate or diacetate was mixed with glass-ionomer cements and tested in vitro against strains of Lactobacillus casei and mutans streptococci. A spectrophotometric test was used to monitor the release of chlorhexidine from the mixture. In a broth culture test, the higher the concentrations of chlorhexidine in the mixture, the longer the time of antibacterial effect on Streptococcus mutans and the greater the tendency of the material to deteriorate. Agar diffusion tests revealed bacterial inhibition in a dose-response manner. The tested bacterial strains were similarly inhibited and the antibacterial properties decreased with time. A minor portion of added chlorhexidine was released from the cement. The deterioration of the cements indicates that the material could be useful as a varnish-like chlorhexidine carrier.
Acrylic Resins↗
Simplified method to estimate salivary buffer capacity.
A new and simplified method to estimate the salivary buffer capacity was tested. The method, Dentobuff Strip, consists of a pH indicator paper that has been impregnated with acid. A small volume of saliva is added to the strip and after 5 min the color of the strip is compared with a chart. The colors have been chosen to indicate low, medium, or good buffer capacity. The buffer capacity of stimulated saliva samples from 62 subjects was measured with the new method and compared with two commonly used clinical methods, Dentobuff, and an electrometric method. The three methods correlated well, and patients with a low salivary buffer capacity (final pH less than or equal to 4), according to the electrometric method, were readily identified with the new Dentobuff Strip method.
Buffers↗
N-acetylcysteine added to saliva does not affect IgA concentration or the agglutination of Streptococcus mutans in vitro.
N-acetylcysteine (NAC) or placebo were mixed with parotid or whole saliva to a final concentration of 0.004-10 mg/ml saliva. Placebo and NAC-containing parotid saliva had the same bacterial agglutinating capacity for 4 strains of Streptococcus mutans. Immunoglobulin A (IgA) concentration in whole saliva, using ELISA and single radial immunodiffusion assays, did not reveal any differences between NAC and placebo-treated samples. NAC did not affect the immunoelectrophoretic pattern of IgA.
Acetylcysteine↗
Labeling of binding sites for beta 2-microglobulin (beta 2m) on nonfibrillar surface structures of mutans streptococci by immunogold and beta 2m-gold electron microscopy.
As little detail is known about the surface structure of streptococci in the mutans group and the relationship of surface structure to host ligand-binding functions, the twofold purpose of this investigation was to examine in detail, by a range of electron microscopic techniques, the surface structures of streptococci in the different species of the mutans group and to investigate the distribution of beta 2-microglobulin (beta 2m)-binding sites on such structures. Strains representing Streptococcus mutans, S. cricetus, S. rattus, S. sobrinus, and four fresh isolates were studied by shadowcasting and histochemical staining of whole-mounted cells as well as by ultrathin and thick sectioning of embedded specimens. beta 2m-binding site distribution was visualized by indirect immunogold electron microscopy and by direct bacterial binding of beta 2m-conjugated gold probes. Shadowcast preparations revealed binding of gold probes to the cell surface of known beta 2m-binding strains but not to their polar fibrillar appendages. These long fibrils, common to all strains, were trypsin and sonication sensitive and stained with lead citrate but not with uranyl acetate or ruthenium red. More gold particles were bound by the indirect technique. For grid-mounted bacteria, the gold was mostly bound in clusters at the periphery of the cells. When gold probes were reacted in suspension with bacteria before mounting onto grids, a more even distribution of the gold was seen, but the bacteria were aggregated. Heating the bacteria eliminated beta 2m-gold binding but had no effect on the morphology of the fibrils. Thick sections of embedded bacteria prereacted with beta 2m-conjugated gold probes were analyzed by stereo imaging. A wispy, uranyl acetate-stained fuzzy layer, distinct from the fibrils seen by shadowcasting and extending up to one cell diameter from the cell wall, contained the gold probes. These findings introduce a concept that binding sites for some salivary ligands on mutans streptococci may be clustered on very delicate, nonfibrillar structures extending much further from the cell wall than previously appreciated. As for beta 2m, which composes part of the human histocompatibility antigens, part of the bacterial surface would be coated at a distance from its body with a protein not necessarily recognized as foreign by the host.
Animals↗
Antimicrobial action of new, proprietary lining cements.
The antibacterial activity of innovative, commercial lining cements was investigated. A liner which contains calcium hydroxide and is polymerized by visible light (Prisma VLC Dycal) and a glass-ionomer lining cement (GC lining cement) were compared with two more established lining cements (Advanced Formula II Dycal and Life). Antibacterial activity and hemolysis-like agar change at 24, 48, and 72 hours were measured on blood agar plates inoculated with Streptococcus mutans KPSK 2 (serotype c), Lactobacillus casei ssp rhamnosus ATCC 11981, and chewing-stimulated saliva. Prisma VLC Dycal did not affect bacteria or agar. The glass-ionomer lining cement, with an acidic pH at setting, had the most pronounced effect on all test organisms and on the agar. Even after 48 hours' setting, it inhibited growth of S. mutans. The control lining cement (AFII Dycal) showed antibacterial activity toward both specific micro-organisms as well as some activity against the salivary organisms. The material Life showed only partial inhibition of microbial growth. For all lining cements, the hemolytic-like agar change correlated with antibacterial effects. The surface pH of the freshly-set cements containing calcium hydroxide was alkaline. It would seem that a simple correlation between high surface pH and antibacterial activity among these cements does not exist. Also, further biological characterization of new lining cements is required to direct their appropriate clinical use.
Anti-Infective Agents, Local↗
Absorption of fibronectin from human saliva by strains of oral streptococci.
Freshly collected human submandibular/sublingual saliva contained between 1.0 and 26.1 micrograms/ml of fibronectin as determined by ELISA. 10(9) organism of 12 oral streptococcal strains tested removed between 2.6 and 89.4% of the fibronectin present in 400 microliters saliva. Fibronectin was retained in bacterial pellets after washings in buffer but could be eluted using 1 M NaCl.
Absorption↗
Fibronectin in saliva and gingival crevices.
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Adult↗
Salivary interactions with homologous and heterologous strains of oral streptococci and epithelial cells.
Twenty strains of oral streptococci resembling the species of Streptococcus mitior and Streptococcus salivarius were isolated from four subjects and were incubated with homologous and heterologous whole clarified saliva. Supernatants of bacterially absorbed and control saliva were analyzed in tandem crossed immunoelectrophoresis (TCIE) against a rabbit anti-human saliva antiserum. Six to eight antigens were detected. After incubation with the bacteria, the saliva supernatants showed a decrease in the number of antigens detectable by TCIE. For all four salivas tested, the homologous group of strains absorbed fewer antigens. Some of the antigens could be eluted from bacterial pellets with 1 M NaCl after repeated washings in PBS. Epithelial cells also absorbed fewer antigens from homologous than heterologous saliva.
Adult↗
Agglutination of Streptococcus mutans by low-molecular-weight salivary components: effect of beta 2-microglobulin.
Radiolabeled monomeric human beta 2-microglobulin (beta 2m) was tested for binding to Streptococcus mutans strains in buffers containing 1 mM calcium (Ca2+). Binding was seen to strains with a previously established binding capacity of aggregated beta 2m. Monomeric beta 2m agglutinated beta 2m-binding strains when Ca2+ was present. At Ca2+ concentrations of 1.4 mM, 0.032 micrograms of monomeric beta 2m per ml caused bacterial agglutination. Parotid saliva was gel filtered on a Sephadex G-75 column, and low-molecular-weight fractions containing beta 2m could agglutinate S. mutans cells. Five of six strains that could bind beta 2m were agglutinated by these fractions, but only one of five nonbinding strains was. All strains tested were agglutinated by void volume fractions. A new method for the measurement of turbidity in bacterial agglutination inhibition experiments with parotid saliva was used. Suspensions containing parotid saliva, bacteria, and control serum were directly compared in a spectrophotometer with test suspensions containing goat anti-human beta 2m, bacteria, and saliva. Thus, the spectrophotometer directly read the difference in agglutination of the two suspensions, and the result was presented as one curve by the recorder. Agglutination of five beta 2m-binding strains of S. mutans was inhibited or decreased by the addition of goat anti-human beta 2m as compared with control serum. The agglutination of two beta 2m-nonbinding strains and one with variable binding was not inhibited. Thus, salivary beta 2m may contribute to agglutination of S. mutans cells in parotid saliva.
Adhesiveness↗
beta 2-Microglobulin in saliva and its relation to flow rate in different glands in man.
The concentration of beta 2-microglobulin (beta 2-m) in parotid saliva and sera from 13 adult hypogammaglobulinaemic subjects and in parotid saliva from 7 normal adults was determined by radioimmunoassay. Parotid and submandibular/sublingual saliva was collected from four normal and one hypogammaglobulinaemic subject in unstimulated and stimulated samples, and concentrations of IgA and beta 2-m were determined. The beta 2-m concentration in parotid saliva from hypogammaglobulinaemic subjects was 0.50 mg/l (0.2-1.1) and in normal adults 0.41 mg/l (0.2-0.9). In parotid saliva, the concentration of beta 2-m was negatively correlated with the flow rate, whereas in submandibular/sublingual a positive correlation was seen. Serum levels of beta 2-m in hypogammaglobulinaemic subjects were within the normal range of healthy adults. Gel filtration of saliva separated beta 2-m from IgA and from high molecular weight agglutinins. Beta 2-m was eluted as one single peak.
Adult↗
Further characteristics of beta2-microglobulin binding to oral streptococci.
A total of 85 strains of oral bacteria representing Streptococcus mutans, S. sanguis, S. Mitior, S. salivarious, S. milleri, S. infrequens, S. durans, S. lactis, S. faecalis, S. faecium, S. equinus, Streptococcus species group E, Actinomyces, and one group A Streptococcus were tested for binding of aggregated human beta 2-microglobulin. Positive affinity between bacteria and aggregated human beta 2-microglobulin was detected in 36% of the strains. No apparent correlation with bacterial species, serotype, or group was noted. No positive strains were detected among seven group I:A S. sanguis strains (P < 0.01). Binding constants for one S. mutans strain indicated heterogeneous binding structures on the bacterial surface. The number of binding sites for aggregates of human beta 2-microglobulin involving multipoint attachment varied from 70 to 1,700 per bacterial cell. With whole saliva as buffer, a general increase in affinity was seen. Variations in salt concentrations of the buffers revealed different salt-dependent species-associated uptake patterns. Oral bacteria tended to have an uptake maximum at a salt concentration similar to that seen in saliva. Binding structures for aggregated beta 2-microglobulin on oral streptococci were sensitive to pepsin, heat, and formaldehyde treatment. Bacterial binding structures for aggregated beta 2-microglobulin might represent one of several factors of importance for bacterial attachment in the oral cavity. Experimental conditions reflecting the salivary milieu increased the degree of interaction, emphasizing the importance of physiological test systems for such studies.
Actinomyces↗
A new technique for restraint of mice.
One hundred ninety-five mice were restrained for an ear punching and toe clipping identification procedure using a new technique. The unique feature of the restraint method was that the mouse's head was immobilized within a finger loop of surgical scissors.
Animals↗
Interactions between human serum proteins and oral streptococci reveal occurrence of receptors for aggregated beta 2-microglobulin.
A total of 31 strains of oral streptococci representing Streptococcus mutans, Streptococcus sanguis, Streptococcus mitior, Streptococcus salivarius, and Streptococcus milleri were tested for possible binding of human immunoglobulins G, G1, G2, G3, G4, A1, A2, M1, and M2 and haptoglobin, hemoglobin, fibrinogen, and aggregated beta 2-microglobulin. Radiolabeled beta 2-microglobulin in aggregated form showed affinity for 20 of the 31 strains tested. Binding activity for the protein was found in strains belonging to all five species. The bacterial receptor was resistant to trypsin. Monomeric, unlabeled beta 2-microglobulin did not interfere with the binding of the aggregated form. Of the other proteins tested, only the immunoglobulin A1 protein showed positive binding, and that was only with a single strain of S. milleri. beta 2-Microglobulin is present on all nucleated cell membranes in vivo. The reaction between aggregated beta 2-microglobulin and oral streptococci is a new type of human-bacterium interaction which should be considered in studies of bacterial adherence.
Beta-Globulins↗
Proceedings for the 5th Asia-Pacific Conference on Disaster Medicine: creating an agenda for action.
Disaster medicine has come to the forefront and has become the focus of interest not only in the medical community, but also in the eyes of the public. The 5th APCDM was convened in Vancouver, Canada, 27-30 September 2000. It brought together over 300 delegates from 32 countries to share their experiences and thoughts regarding disaster events and how to effectively manage them. The conference was devoted to the task of establishing priorities and creating an Agenda for Action. From the discussions, key actions required were defined: COMMUNICATIONS: (1) Identify existing regional telehealth groups and gather lessons to be learned from them; (2) Form a telehealth advisory group to work with regional groups to compile telehealth initiatives, identify international protocols in telehealth already in existence, and solicit feedback before setting international standards; and (3) Increase corporate partnerships in the fields of telehealth and telecommunications, and invite corporations to send delegates to future APCDM meetings. This should be an initiative of the APCDM, the World Association of Disaster and Emergency Medicine (WADEM), or the European Society of Emergency Medicine. EDUCATION AND RESEARCH: (1) Formalize education in disaster medicine and management. The World Health Organization and WADEM should take a leadership role; (2) WADEM is requested to hold a conference with a focus on qualitative research; (3) WHO is requested to continue the provision of international research teams, but to advocate for the development of national disaster research infrastructure; (4) Make research findings and reports available on web sites of such organizations as WHO and PAHO; (5) Develop the translation of research for community utilization. The WHO and PAHO are organizations that are requested to consider this action; and (6) WADEM/APCDM are requested to focus future conferences on applied research. INFORMATION AND DATA: (1) Create an "Information and Data Clearinghouse on Disaster Management" to collect, collate, and disseminate information; (2) Collect data using standardized tools, such as CAR or Hazmat indices; (3) Analyze incentives and disincentives for disaster readiness and establish mechanisms for addressing the obstacles to preparedness; and (4) WADEM is requested to develop a web site providing a resource list of interdisciplinary institutions and response activities, organized by country, topic, and research interests. Links to other pertinent web sites should be provided. INTERDISCIPLINARY DEVELOPMENT: (1) Focus on the interdisciplinary nature of disaster response through more conferences encompassing grassroots efforts and through WADEM publications; (2) Develop and apply a standardized template of Needs Assessment for use by multidisciplinary teams. Team Needs Assessment is essential to determine the following: (a) Local response and international assistance required; (b) Appropriate command system; and (c) Psychosocial impact and support necessary. PSYCHOSOCIAL ASPECTS: (1) Incorporate relief for caregivers into action plans. This should include prime family members who also are caregivers; and (2) Implement measures that give survivors control over the recovery process. RESPONSE MANAGEMENT: (1) Define relationships and roles between governments, military and security personnel, non-governmental organizations (NGOs), and civic groups. Use an international legal framework and liability to reinforce accountability of disaster responders; (2) Establish a more sophisticated use of the media during disasters; (3) Establish standards in key areas. WADEM is requested to write "White Papers" on standards for the following areas: (a) management, (b) health/public health, (c) education/training, (d) psychosocial, and (e) disaster plans; (4) Establish task forces to anticipate and resolve issues around evolving and emerging disasters (e.g., chemical and biological terrorism, landmines, emerging infectious diseases). WADEM was again identified as the vehicle for promoting this action. The responsibility of the next meeting of the Asia-Pacific Conference on Disaster Medicine will be to measure progress made in these areas by assessing how well these collective decisions have been implemented.
Databases, Factual↗
Clinical evaluation of efficacy and safety of a new method for chemo-mechanical removal of caries. A multi-centre study.
The aim of the study was to evaluate the clinical efficacy and safety of a new method (Carisolvtrade mark) for chemo-mechanical removal of caries. At four centres, 137 consecutive patients (64 females and 73 males aged 3-85 years, mean 35) entered a prospective, controlled, randomised open study. One primary caries lesion with distinct dentine involvement was selected per patient. A total of 116 lesions in permanent and 21 in deciduous teeth were selected. Caries was removed with traditional drilling or the new method. Gel was applied onto the carious dentine and the softened caries gently removed with specially designed hand instruments. New gel was applied and the procedure was repeated until no more debris could be removed and the surface was hard as judged by clinical criteria (probing and visual inspection). An independent examiner judged the cavity being caries-free or not, using clinical criteria. One hundred and thirteen patients were randomised for gel treatment and 24 for drilling. Three patients selected for drilling did not complete the treatment. Total caries removal was achieved in 106 cases with gel and in 19 with drilling. The reasons for incomplete caries removal were step-by-step excavation in 5 cases, unsuccessful caries removal in 1 case for each treatment, while 2 cases refused inspection. Mean (+/- SD) time for caries removal was 10.4 (+/-6.1) min with the gel method and 4.4 (+/-2.2) min with drilling. Mean volume of gel used was 0.4 (+/-0.2) ml. Eighty-two of 107 patients perceived that the new method caused less discomfort compared to drilling. Dentine caries was effectively removed using the Carisolv method without any adverse reactions.
Adolescent↗