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At least 379 records · Page 21Linked to original sources

PubMed1998

Functional changes in THP-1 human monocytic cells after stimulation with lipopolysaccharide of oral microorganisms and granulocyte macrophage colony stimulating factor.

A human THP-1 monocyte cell line culture system has been utilized to observe the effect of granulocyte macrophage colony stimulating factor (GM-CSF) supplementation with lipopolysaccharide (LPS) of oral microorganisms to stimulate monocyte/macrophage functional activity. LPS of oral microorganisms, Fusobacterium nucleatum and Porphyromonas gingivalis was produced by phenol-water extraction and characterized. The phagocytosis assay was performed using F1TC labeled Saccharomyces yeast particles. Phagocytic functional activity was observed in 10-11% of resting THP-1 cells. Treatment of THP-1 cells with LPS of F. nucleatum or P. gingivalis increased the phagocytic activity of THP-1 cells 2-3 fold. GM-CSF significantly increased phagocytosis either alone or when supplemented with LPS of F. nucleatum or P. gingivalis. A chemotaxis assay was performed using a 48 well chemotaxis chamber. Chemotactic functional activity of THP-1 cells was increased 2-fold after 4 days of treatment with GM-CSF. Stimulation of THP-1 cells with LPS of F. nucleatum or P. gingivalis significantly reduced the chemotactic activity indicating the maturation towards a fixed macrophage. There were functional variations (chemotaxis and phagocytosis) in THP-1 cells in response to LPS of oral microorganisms following stimulation with GM-CSF.

Cell Line↗

PubMed1992

[The microbial colonization of implant elements made of plastics and titanium].

12 edentate subjects wearing lower complete dentures stabilized by an IMZ-implant-supported Dolder bar took part in the experiment. Elastic (POM) and titanium connection parts were alternatingly inserted. After the removal of 24 POM and titanium elements from each of the patients, a qualitative analysis of the microbial flora was performed. Except for actinomycetes, aerobic as well as anaerobic microorganisms were found less frequently with titanium than with POM elements.

Actinomycetales↗

PubMedDate not supplied

[The antilysozyme activity of yeasts in the genus Candida].

The fungi of the genus Candida isolated from patients with oral mucosa candidiasis and from candidiasis carriers have been studied for their antilysozyme activity. These fungi (Candida albicans, C. tropicalis, C. krusei, C. quilliermondii) are antilysozyme-active. A high antilysozyme activity of the fungi isolated from patients with oral mucosa candidiasis permits supposing that the presence of this trait may be one of the factors of microorganism pathogenicity. The effective antimycotic therapy (clotrimasole, sanguirhitrin) decreases the antilysozyme activity of fungi of the genus Candida.

Alkaloids↗

PubMed1993

Antibiotics for acute orofacial infections.

By virtue of their activity against common and microbial pathogens, three antibiotic groups have real or potential application in the routine management of acute orofacial infections: beta-lactams (penicillins and cephalosporins), macrolides (erythromycin and congeners) and the lincosamides (clindamycin). The beta-lactam agents, principally the penicillins, remain drugs of choice. The macrolides have gained a resurgence in popularity due to their low toxicity, improved pharmacokinetics with azithromycin and clarithromycin, and the ability to penetrate into white blood cells to attack intracellular microorganisms. Clindamycin may be useful in penicillin-allergic patients and when directed by culture and sensitivity tests.

Acute Disease↗

PubMed1988

Fulminant postsplenectomy sepsis.

The vital role of a normally-functioning spleen in a host's defence against circulating microorganisms has been realized for many years. The fulminant clinical course that characterizes infection with encapsulated microorganisms in asplenic patients is highlighted in these cases of severe pneumococcal sepsis in two patients, 10 and 13 years after splenectomies for idiopathic thrombocytopenic purpura. Approaches to the acute management of septic episodes and preventive measures are discussed. Pneumococcal vaccination reduces the incidence of infection effectively in asplenic patients and has a low complication rate. Penicillin by mouth is also efficacious in this situation, but patient compliance is low. Our current practice is to offer pneumococcal vaccination to all patients who have undergone splenectomy in the past and to administer the vaccine two weeks before elective splenectomies. Asplenic patients should be educated about the potential dangers of a septic episode and should be urged to seek an early medical consultation when this occurs.

Acute Disease↗

PubMed1993

A SEM study of denture plaque and oral mucosa of denture-related stomatitis.

The aim of this study was to compare the morphology of denture plaque and adjacent palatal mucosa in five subjects with denture-related stomatitis and a control group of five healthy subjects. Scanning electron microscope examination of copper plate replicas, which preliminary studies established were superior to epoxy resin replicas, showed that there were no consistent differences between the morphology of denture plaque and adjacent mucosa in the denture-related stomatitis group and control group. In each, the surface of the denture plaque was composed predominantly of coccoid- and rod-shaped bacteria with only some yeast cells. The mucosa was largely devoid of microorganisms and individual epithelial cells were shedding from its surface.

Bacteria↗

PubMed1987

Denture plaque and palatal mucosa in denture stomatitis: scanning electron microscopic and microbiologic study.

Denture plaque is an etiologic factor in denture stomatitis. In this study, denture and mucosa samples from nine patients were examined in the SEM and processed for microbiologic cultures. Denture plaque in patients with denture stomatitis showed a considerable thickness containing cocci, filaments, rods, yeasts, and desquamated epithelial cells. Some microorganisms were revealed in the connective tissue in one patient and phagocytizing polymorphonuclear leukocytes were found in the palatal mucosa of the patients with denture stomatitis.

Bacteria↗

PubMed1975

Intraoral actinomycosis. Report of five cases.

Five intraoral presentations of actinomycetes are recorded, in three of which the infection was almost certainly specifically due to the microorganisms. The importance of careful histopathologic examination is underlined, and the failure in some cases to investigate apparently simple infections bacteriologically is highlighted.

Abscess↗

PubMed1982

A retrospective study of microbiologic samples from oral mucosal lesions.

This report describes findings in microbial samples from 271 patients with lesions of the oral mucous membranes. Analyses were made on the basis of direct microscopy and cultivation on nonselective and selective media incubated under aerobic and anaerobic conditions. Growth of bacteria was semiquantitatively determined according to a five-grade scale. Among the 134 samples for direct microscopy, fungi in yeast as well as hyphae phase, were identified in 39 cases. Among the cultivated samples, Candida albicans was detected in 107 cases, of which 71 were full-denture wearers. Staphylococcus aureus, coliform bacteria and Klebsiella were the most frequently isolated "nonoral" bacteria. In some cases also Streptococcus pyogenes, Haemophilus influenzae, Pseudomonas or other gram-negative aerobic bacteria were found. In 84 cases the bacteria mentioned were registered as single "nonoral" infection, and in 63 cases combinations of "nonoral" species occurred. In 51 of these 63 cases C. albicans was also involved. In 31 cases a significant quantitative increase of one or more oral bacterial species was registered. In 93 cases there was no indication of a microbial cause of the lesion. On the basis of these microbial findings, it might be presupposed that in the majority of cases microorganisms were of primary or secondary pathogenic importance to the lesions.

Adolescent↗

PubMed1997

Arbitrarily primed polymerase chain reaction fingerprinting and clonal analysis of oral Fusobacterium nucleatum isolates.

F. nucleatum is the most commonly isolated microorganism from subgingival plaque, but the role of this microorganism in periodontal diseases remains undefined. Arbitrarily primed polymerase chain reaction (AP-PCR) was evaluated as a method for fingerprinting F. nucleatum isolates and for use in clonal analysis. Pulsed field gel electrophoresis was used to further differentiate F. nucleatum isolates, with identical AP-PCR patterns. Extremely heterogeneous AP-PCR fingerprints were observed among the 98 F. nucleatum isolates, with 36 different genotypes observed with primer C1 and 30 different genotype detected with primer C2. Combining the results of the AP-PCR genotype analysis from C1 and C2 primer amplifications revealed that up to 7 different genotypes could be distinguished from isolates from the same oral cavity and that up to 4 different genotypes were observed within a single site. An intense amplicon at approximately 450 bp generated in AP-PCR amplification with primer C2 was associated with F. nucleatum subsp. nucleatum (ATCC 25586) and with 15 F. nucleatum isolates from diseased sites and 2 isolates from healthy sites. Pulsed field gel electrophoresis confirmed the AP-PCR genotypes and demonstrated increased discriminatory power over AP-PCR. The results indicated that AP-PCR and pulsed field gel electrophoresis provide a simple and sensitive means for differentiating oral F. nucleatum isolates and further demonstrate the heterogeneity of this species. These techniques may serve as useful tools in the clonal and epidemiological analysis of F. nucleatum isolates, which may help define the role of these microorganisms in periodontal diseases.

Bacterial Typing Techniques↗

PubMed2004

Clinical and microbiological effects of topical subgingival application of hyaluronic acid gel adjunctive to scaling and root planing in the treatment of chronic periodontitis.

BACKGROUND: Hyaluronic acid (HA) has shown anti-inflammatory effects in gingivitis therapy. The potential benefits of local subgingival application of HA adjunctive to scaling and root planing (SRP) were evaluated in this study. METHODS: Twenty patients with chronic periodontitis were included in this split-mouth study. Sulcus fluid flow rate (SFFR) and sulcus bleeding index were monitored at baseline and after 1, 2, 3, 4, 5, 6, and 12 weeks; probing depth and clinical attachment level were monitored at baseline and 6 and 12 weeks. Subgingival plaque samples were also taken at these same three appointments to determine the presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, and Treponema denticola. All patients were treated with full-mouth scaling and root planing (SRP); in addition, an HA gel was administered subgingivally in the test sites every week for 6 weeks. RESULTS: An improvement of all clinical variables was observed (P < 0.05) in both groups. Clinically, no difference between test and control sites could be found. No difference between test and control sites was seen in the tested microorganisms. CONCLUSIONS: No clinical or microbiological improvement was achieved by the adjunctive use of HA gel compared to SRP alone. Only SFFR was affected by the use of HA in terms of a more rapid reduction of SFFR in the test sites.

Administration, Topical↗

PubMed2006

[Isolation of Helicobacter pylori in gastric mucosa, dental plaque and saliva in a population from the Venezuelan Andes].

Helicobacter pylori infection is common in people. However, the existence of extra gastric reservoirs and transmission routes remain controversial in the field. Because the oral cavity has been proposed as a reservoir for H. pylori, a study was carried out to determine the presence of H. pylori in dental plaque and saliva. The results were asociated with those obtained in the gastric biopsy. Ninety-seven dyspeptic and fifty asymptomatic patients were studied and samples taken for biopsy, dental plaque and saliva. The gastric biopsies were evaluated using microbiology and histology methods. Cultures and urease tests were carried out on the oral cavity samples and included pretreatment methods using urea and HCl. The frequency of H. pylori for all the patients evaluated was 75.5%. H. pylori was not isolated in saliva or dental plaque in any of the two groups studied with or without sample pretreatment. The urease test in dental plaque was positive in 99.3% of the patients and 89.8% in saliva. There was no statistically significant difference between the infection prevalence by H. pylori in dyspeptic or not dyspeptic patients. The obtained results suggest that the methodology used for the detection of H. pylori is not sufficiently sensitive for the determination of the microorganism in the oral cavity.

Adolescent↗

PubMed1986

Hardness changes and mineral loss in enamel during the intra oral cariogenicity test in the presence of 0.125% EHDP with or without 0.1% F-.

The effects of a high EHDP concentration (0.125%) were measured under Intra Oral Cariogenicity Test (ICT) conditions in the presence or absence of F- (0.1%). EHDP as well as EHDP supplemented with F- inhibited the softening of enamel slabs to a similar extent as measured by microhardness. Measurements of the calcium and phosphate levels as a function of depth showed that the addition of F- to the EHDP solution further decreased mineral loss in the deeper layers. The results suggest that the inhibition of demineralization of the enamel by EHDP and F- is due to inhibition of acid production by microorganisms.

Calcium↗

PubMed1978

Streptococcus mutans, an assessment of its physiological potential in relation to dental caries.

Streptococcus mutans converts low levels of sucrose to lactic acid, but at high levels favours synthesis of glucans for plaque accumulation. Thus, the continued exposure to sucrose fluxes would select microorganisms in the oral cavity (S. mutans being a prototype) with highly specialized adaptation and potential dental caries activity. The bacteria that have evolved physiological systems to function efficiently under these conditions are the lactic acid bacteria. These organisms survive in environments where carbohydrate availability is constantly changing. High tolerances to acidic environments may be an important determinant in establishing the ecology of the carious lesion. Also, the intercellular polysaccharide storgae (glycogenamylopectin) and extracellular polymer reserves (levan and soluble glucan) are important during carbohydrate depletion. Further, the formation of insoluble glucans is a prerequisite for the caries process on smooth surfaces of teeth through plaque development. These conditions could result in an increase in S. mutans and cariogenic microorganisms. As a result, this process may be best understood as a manifestation of an amphibiotic shift.

Carbohydrate Metabolism↗

PubMed1997

The size distribution of droplets in the exhaled breath of healthy human subjects.

Droplets carried in exhaled breath may carry microorganisms capable of transmitting disease over both short and long distances. The size distribution of such droplets will influence the type of organisms that may be carried as well as strategies for controlling airborne infection. The aim of this study was to characterize the size distribution of droplets exhaled by healthy individuals. Exhaled droplets from human subjects performing four respiratory actions (mouth breathing, nose breathing, coughing, talking) were measured by both an optical particle counter (OPC) and an analytical transmission electron microscope (AEM). The OPC indicated a preponderance of particles less than 1 mu, although larger particles were also found. Measurements with the AEM confirmed the existence of larger sized droplets in the exhaled breath. In general, coughing produced the largest droplet concentrations and nose breathing the least, although considerable intersubject variability was observed.

Adult↗

PubMed2000

The effectiveness of 10% chlorhexidine varnish treatment on dental caries incidence in adults with dry mouth.

OBJECTIVES: This study compared a 10% chlorhexidine varnish treatment with placebo and sham treatments for preventing dental caries in adult patients with xerostomia (dry mouth). DESIGN: The study was a multicentred, randomized, parallel group, double blind, placebo-controlled clinical trial. SETTING: All examinations and procedures were performed at Tuft's University, Boston, MA, the University of British Columbia, Vancouver, BC or the University of Western Ontario, London, ON. SUBJECTS: Subjects were adults with recent or current dental caries experience, high salivary levels of cariogenic microorganisms and low salivary flow rates. RESULTS: 236 subjects completed at least one post-treatment examination. There were 697 new carious lesions diagnosed, 446 (64%) located on coronal surfaces and 251 (36%) located on root surfaces. The mean attack rate was 0.23 surfaces/100 surfaces at risk. A treatment difference observed between the Active and Placebo groups was statistically significant for root caries increment (p = .02) and total caries increment (p = .03). A treatment difference observed between the Active and Sham groups was not statistically significant for coronal, root or total caries increment. Analysis of variance of treatment group differences was performed using mutans streptococci counts, salivary flow rates, age, sex, caries prevalence, medications, time to first event and early withdrawal as co-variables. These factors did not meaningfully alter the findings. CONCLUSIONS: The difference between the 10% chlorhexidine varnish and placebo treatments is considered to be highly clinically significant for root caries increment (41% reduction) and for total caries increment (25% reduction) but only for coronal caries increment (14%).

Aged↗

PubMed1999

Prevention and management of oral infections in cancer patients.

The successful prevention and management of oral infections and infections from the oral cavity in cancer patients are based on identification of risk patients, selection of patients for prophylactic measures, diagnosis of infection and implementation of directed or empiric antimicrobial therapy. Identification of patients at risk for infection is based on each patient's type of oral microbial colonization and the presence of latent viral infections. Systemic and local resistance to infection will be decisive, and in many patients the risk can be estimated from the expected myelosuppressive effect of anticancer treatment. Diagnosis of infection is often based on clinical findings together with the results of microbiological investigations. Biopsies could be useful, but can seldom be obtained. Blood samples are mandatory for isolation of microorganisms involved in systemic infections in myelosuppressed patients. Prevention of infection requires both local and systemic measures. Elimination of the risk of a breach in the first line of defence is urgent, and the maintenance of mucosal integrity is important. Monitoring microbial colonization is common, as is the institution of antiviral prophylaxis in patients with increased anti-HSV IgG (ELISA > 10,000). Antifungal prophylaxis, to avoid colonization and superinfection, should be instituted in patients with low neutrophil counts. Gastrointestinal prophylaxis with quinolones is also commonly used in these patient groups. Treatment of oral infections in cancer patients should include systemic antimicrobial agents in most cases. Special attention should be directed to oral infections in neutropenic (< 0.5 x 10(9)/1) patients in whom oral microorganisms are the leading cause of bacteraemia. Invasive fungal infections of the oral cavity can be associated with systemic fungal infection and are indications for the use of liposomal amphotericin B.

Female↗

PubMed1993

Osteomyelitis of the mandible in Tehran, Iran. Analysis of 88 cases.

This study involved 88 cases of different types of osteomyelitis of the mandible. Sixty-nine patients had osteomyelitis after trauma, eight patients after radiotherapy, six after dental infection, and six had other causes. Thirty-three patients had septicemic infection. Multiple types of aerobic and nonaerobic microorganisms were isolated from the infection sites. Types of treatment and their results are discussed.

Adolescent↗